Association Between Predeployment Optimism and Onset of Postdeployment Pain in US Army Soldiers | Pain Medicine | JAMA Network Open | JAMA Network
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Figure 1.  Flow Diagram of the Sample Selection
Flow Diagram of the Sample Selection

aBaseline pain refers to back pain, joint pain, or frequent headaches before deployment.

Figure 2.  Optimism and Odds of Reporting New Frequent Headaches by Marital Status
Optimism and Odds of Reporting New Frequent Headaches by Marital Status

The odds ratio for not married was 1.05 (95% CI, 0.96-1.14); married, 0.89 (95% CI, 0.83-0.97). Error bars indicate 95% CIs.

Table 1.  Distribution of Demographic, Military, and Health Covariates Among 20 734 US Army Soldiers
Distribution of Demographic, Military, and Health Covariates Among 20 734 US Army Soldiers
Table 2.  Association Between Continuous Optimism and Incident Postdeployment Pain
Association Between Continuous Optimism and Incident Postdeployment Pain
Table 3.  Association Between Optimism (Tertiles) and Incident Postdeployment Paina
Association Between Optimism (Tertiles) and Incident Postdeployment Paina
1.
Institute of Medicine.  Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research. Washington, DC: National Academy of Sciences; 2011.
2.
US Army Public Health Center. 2017 Health of the Force. https://phc.amedd.army.mil/Periodical%20Library/2017HealthoftheForceReportWeb_Printer.pdf. Published 2017. Accessed November 13, 2018.
3.
Cohen  SP, Brown  C, Kurihara  C, Plunkett  A, Nguyen  C, Strassels  SA.  Diagnoses and factors associated with medical evacuation and return to duty for service members participating in Operation Iraqi Freedom or Operation Enduring Freedom: a prospective cohort study.  Lancet. 2010;375(9711):301-309. doi:10.1016/S0140-6736(09)61797-9PubMedGoogle Scholar
4.
Cifu  DX, Taylor  BC, Carne  WF,  et al.  Traumatic brain injury, posttraumatic stress disorder, and pain diagnoses in OIF/OEF/OND Veterans.  J Rehabil Res Dev. 2013;50(9):1169-1176. doi:10.1682/JRRD.2013.01.0006PubMedGoogle Scholar
5.
Lew  HL, Cifu  DX, Crowder  T, Hinds  SR.  National prevalence of traumatic brain injury, posttraumatic stress disorder, and pain diagnoses in OIF/OEF/OND Veterans from 2009 to 2011.  J Rehabil Res Dev. 2013;50(9):xi-xiv. doi:10.1682/JRRD.2013.09.0212PubMedGoogle Scholar
6.
Toblin  RL, Quartana  PJ, Riviere  LA, Walper  KC, Hoge  CW.  Chronic pain and opioid use in US soldiers after combat deployment.  JAMA Intern Med. 2014;174(8):1400-1401. doi:10.1001/jamainternmed.2014.2726PubMedGoogle Scholar
7.
Gironda  RJ, Clark  ME, Massengale  JP, Walker  RL.  Pain among veterans of Operations Enduring Freedom and Iraqi Freedom.  Pain Med. 2006;7(4):339-343. doi:10.1111/j.1526-4637.2006.00146.xPubMedGoogle Scholar
8.
Phillips  KM, Clark  ME, Gironda  RJ,  et al.  Pain and psychiatric comorbidities among two groups of Iraq and Afghanistan era Veterans.  J Rehabil Res Dev. 2016;53(4):413-432. doi:10.1682/JRRD.2014.05.0126PubMedGoogle Scholar
9.
Bosco  MA, Murphy  JL, Clark  ME.  Chronic pain and traumatic brain injury in OEF/OIF service members and Veterans.  Headache. 2013;53(9):1518-1522.PubMedGoogle Scholar
10.
Forman-Hoffman  VL, Peloso  PM, Black  DW, Woolson  RF, Letuchy  EM, Doebbeling  BN.  Chronic widespread pain in veterans of the first Gulf War: impact of deployment status and associated health effects.  J Pain. 2007;8(12):954-961. doi:10.1016/j.jpain.2007.07.003PubMedGoogle Scholar
11.
Helmer  DA, Chandler  HK, Quigley  KS, Blatt  M, Teichman  R, Lange  G.  Chronic widespread pain, mental health, and physical role function in OEF/OIF veterans.  Pain Med. 2009;10(7):1174-1182. doi:10.1111/j.1526-4637.2009.00723.xPubMedGoogle Scholar
12.
Lewis  JD, Wassermann  EM, Chao  W, Ramage  AE, Robin  DA, Clauw  DJ.  Central sensitization as a component of post-deployment syndrome.  NeuroRehabilitation. 2012;31(4):367-372.PubMedGoogle Scholar
13.
Ramirez  S, Bebarta  VS, Varney  SM, Ganem  V, Zarzabal  LA, Potter  JS.  Misuse of prescribed pain medication in a military population: a self-reported survey to assess a correlation with age, deployment, combat illnesses, or injury?  Am J Ther. 2017;24(2):e150-e156. doi:10.1097/MJT.0000000000000141PubMedGoogle Scholar
14.
Granado  NS, Pietrucha  A, Ryan  M,  et al.  Longitudinal assessment of self-reported recent back pain and combat deployment in the Millennium Cohort Study.  Spine (Phila Pa 1976). 2016;41(22):1754-1763. doi:10.1097/BRS.0000000000001739PubMedGoogle Scholar
15.
Uomoto  JM, Esselman  PC.  Traumatic brain injury and chronic pain: differential types and rates by head injury severity.  Arch Phys Med Rehabil. 1993;74(1):61-64.PubMedGoogle Scholar
16.
Wells  TS, LeardMann  CA, Fortuna  SO,  et al; Millennium Cohort Study Team.  A prospective study of depression following combat deployment in support of the wars in Iraq and Afghanistan.  Am J Public Health. 2010;100(1):90-99. doi:10.2105/AJPH.2008.155432PubMedGoogle Scholar
17.
Ramchand  R, Schell  TL, Karney  BR, Osilla  KC, Burns  RM, Caldarone  LB.  Disparate prevalence estimates of PTSD among service members who served in Iraq and Afghanistan: possible explanations.  J Trauma Stress. 2010;23(1):59-68.PubMedGoogle Scholar
18.
Vasterling  JJ, Proctor  SP, Friedman  MJ,  et al.  PTSD symptom increases in Iraq-deployed soldiers: comparison with nondeployed soldiers and associations with baseline symptoms, deployment experiences, and postdeployment stress.  J Trauma Stress. 2010;23(1):41-51.PubMedGoogle Scholar
19.
Quartana  PJ, Wilk  JE, Balkin  TJ, Hoge  CW.  Indirect associations of combat exposure with post-deployment physical symptoms in U.S. soldiers: roles of post-traumatic stress disorder, depression and insomnia.  J Psychosom Res. 2015;78(5):478-483. doi:10.1016/j.jpsychores.2014.11.017PubMedGoogle Scholar
20.
Hoopsick  RA, Vest  BM, Homish  DL, Homish  GG.  Combat exposure, emotional and physical role limitations, and substance use among male United States Army Reserve and National Guard soldiers.  Qual Life Res. 2018;27(1):137-147. doi:10.1007/s11136-017-1706-2PubMedGoogle Scholar
21.
Finan  PH, Quartana  PJ, Smith  MT.  Positive and negative affect dimensions in chronic knee osteoarthritis: effects on clinical and laboratory pain.  Psychosom Med. 2013;75(5):463-470. doi:10.1097/PSY.0b013e31828ef1d6PubMedGoogle Scholar
22.
Rasmussen  HN, Scheier  MF, Greenhouse  JB.  Optimism and physical health: a meta-analytic review.  Ann Behav Med. 2009;37(3):239-256. doi:10.1007/s12160-009-9111-xPubMedGoogle Scholar
23.
DuBois  CM, Lopez  OV, Beale  EE, Healy  BC, Boehm  JK, Huffman  JC.  Relationships between positive psychological constructs and health outcomes in patients with cardiovascular disease: a systematic review.  Int J Cardiol. 2015;195:265-280. doi:10.1016/j.ijcard.2015.05.121PubMedGoogle Scholar
24.
Schiavon  CC, Marchetti  E, Gurgel  LG, Busnello  FM, Reppold  CT.  Optimism and hope in chronic disease: a systematic review.  Front Psychol. 2017;7:2022. doi:10.3389/fpsyg.2016.02022PubMedGoogle Scholar
25.
Goodin  BR, Glover  TL, Sotolongo  A,  et al.  The association of greater dispositional optimism with less endogenous pain facilitation is indirectly transmitted through lower levels of pain catastrophizing.  J Pain. 2013;14(2):126-135. doi:10.1016/j.jpain.2012.10.007PubMedGoogle Scholar
26.
Goodin  BR, Kronfli  T, King  CD, Glover  TL, Sibille  K, Fillingim  RB.  Testing the relation between dispositional optimism and conditioned pain modulation: does ethnicity matter?  J Behav Med. 2013;36(2):165-174. doi:10.1007/s10865-012-9411-7PubMedGoogle Scholar
27.
Sobol-Kwapinska  M, Bąbel  P, Plotek  W, Stelcer  B.  Psychological correlates of acute postsurgical pain: a systematic review and meta-analysis.  Eur J Pain. 2016;20(10):1573-1586. doi:10.1002/ejp.886PubMedGoogle Scholar
28.
Goodin  BR, Bulls  HW.  Optimism and the experience of pain: benefits of seeing the glass as half full.  Curr Pain Headache Rep. 2013;17(5):329. doi:10.1007/s11916-013-0329-8PubMedGoogle Scholar
29.
Shrestha  A, Cornum  BGR, Vie  LL, Scheier  LM, Lester  MAJPB, Seligman  MEP.  Protective effects of psychological strengths against psychiatric disorders among soldiers.  Mil Med. 2018;183(suppl_1):386-395. doi:10.1093/milmed/usx189PubMedGoogle Scholar
30.
Vie  LL, Griffith  KN, Scheier  LM, Lester  PB, Seligman  ME.  The Person-Event Data Environment: leveraging big data for studies of psychological strengths in soldiers.  Front Psychol. 2013;4:934. doi:10.3389/fpsyg.2013.00934PubMedGoogle Scholar
31.
Vie  LL, Scheier  LM, Lester  PB, Ho  TE, Labarthe  DR, Seligman  ME.  The U.S. Army Person-Event Data Environment: a military-civilian big data enterprise.  Big Data. 2015;3(2):67-79. doi:10.1089/big.2014.0055PubMedGoogle Scholar
32.
Peterson  C, Park  N, Castro  CA.  Assessment for the U.S. Army Comprehensive Soldier Fitness program: the Global Assessment Tool.  Am Psychol. 2011;66(1):10-18. doi:10.1037/a0021658PubMedGoogle Scholar
33.
Vie  LL, Scheier  LM, Lester  PB, Seligman  MEP.  Initial validation of the U.S. Army Global Assessment Tool.  Mil Psychol. 2016;28(6):468-487. </jrn> doi:10.1037/mil0000141Google Scholar
34.
Scheier  MF, Carver  CS, Bridges  MW.  Distinguishing optimism from neuroticism (and trait anxiety, self-mastery, and self-esteem): a reevaluation of the Life Orientation Test.  J Pers Soc Psychol. 1994;67(6):1063-1078. doi:10.1037/0022-3514.67.6.1063PubMedGoogle Scholar
35.
Clauw  DJ.  Fibromyalgia: a clinical review.  JAMA. 2014;311(15):1547-1555. doi:10.1001/jama.2014.3266PubMedGoogle Scholar
36.
Aaron  LA, Buchwald  D.  A review of the evidence for overlap among unexplained clinical conditions.  Ann Intern Med. 2001;134(9, pt 2):868-881. doi:10.7326/0003-4819-134-9_Part_2-200105011-00011PubMedGoogle Scholar
37.
Hudson  JI, Pope  HG.  The concept of affective spectrum disorder: relationship to fibromyalgia and other syndromes of chronic fatigue and chronic muscle pain.  Baillieres Clin Rheumatol. 1994;8(4):839-856. doi:10.1016/S0950-3579(05)80051-2PubMedGoogle Scholar
38.
Goesling  J, Brummett  CM, Meraj  TS, Moser  SE, Hassett  AL, Ditre  JW.  Associations between pain, current tobacco smoking, depression, and fibromyalgia status among treatment-seeking chronic pain patients.  Pain Med. 2015;16(7):1433-1442. doi:10.1111/pme.12747PubMedGoogle Scholar
39.
Shiri  R, Karppinen  J, Leino-Arjas  P, Solovieva  S, Viikari-Juntura  E.  The association between smoking and low back pain: a meta-analysis.  Am J Med. 2010;123(1):87.e7-87.e35. doi:10.1016/j.amjmed.2009.05.028PubMedGoogle Scholar
40.
Hardt  J, Jacobsen  C, Goldberg  J, Nickel  R, Buchwald  D.  Prevalence of chronic pain in a representative sample in the United States.  Pain Med. 2008;9(7):803-812. doi:10.1111/j.1526-4637.2008.00425.xPubMedGoogle Scholar
41.
Nahin  RL.  Estimates of pain prevalence and severity in adults: United States, 2012.  J Pain. 2015;16(8):769-780. doi:10.1016/j.jpain.2015.05.002PubMedGoogle Scholar
42.
US Department of Defense. Demographics 2010: Profile of the Military Community. http://download.militaryonesource.mil/12038/MOS/Reports/2010-Demographics-Report.pdf. Published 2010. Accessed December 10, 2018.
43.
McLean  SA, Clauw  DJ, Abelson  JL, Liberzon  I.  The development of persistent pain and psychological morbidity after motor vehicle collision: integrating the potential role of stress response systems into a biopsychosocial model.  Psychosom Med. 2005;67(5):783-790. doi:10.1097/01.psy.0000181276.49204.bbPubMedGoogle Scholar
44.
McLean  SA, Williams  DA, Clauw  DJ.  Fibromyalgia after motor vehicle collision: evidence and implications.  Traffic Inj Prev. 2005;6(2):97-104. doi:10.1080/15389580580590931545PubMedGoogle Scholar
45.
Lanier  PJ, Speirs  J, Koehler  L, Bader  J, Abdelgawad  A, Waterman  BR.  Predictors of persistent pain after fixation of distal clavicle fractures in an active military population.  Orthopedics. 2018;41(1):e117-e126. doi:10.3928/01477447-20171127-02PubMedGoogle Scholar
46.
Fishbain  DA, Pulikal  A, Lewis  JE, Gao  J.  Chronic pain types differ in their reported prevalence of post-traumatic stress disorder (PTSD) and there is consistent evidence that chronic pain is associated with PTSD: an evidence-based structured systematic review.  Pain Med. 2017;18(4):711-735.PubMedGoogle Scholar
47.
Lester  PB, Harms  PD, Herian  MN, Sowden  WJ.  A force of change: Chris Peterson and the US Army’s Global Assessment Tool.  J Posit Psychol. 2015;10(1):7-16. doi:10.1080/17439760.2014.927904Google Scholar
48.
Puig-Perez  S, Hackett  RA, Salvador  A, Steptoe  A.  Optimism moderates psychophysiological responses to stress in older people with type 2 diabetes.  Psychophysiology. 2017;54(4):536-543. doi:10.1111/psyp.12806PubMedGoogle Scholar
49.
Kim  ES, Hagan  KA, Grodstein  F, DeMeo  DL, De Vivo  I, Kubzansky  LD.  Optimism and cause-specific mortality: a prospective cohort study.  Am J Epidemiol. 2017;185(1):21-29. doi:10.1093/aje/kww182PubMedGoogle Scholar
50.
Plomin  R, Scheier  MF, Bergeman  CS, Pedersen  NL, Nesselroade  JR, McClearn  GE.  Optimism, pessimism and mental health: a twin/adoption analysis.  Pers Individ Dif. 1992;13(8):921-930.</jrn> doi:10.1016/0191-8869(92)90009-EGoogle Scholar
51.
Kubzansky  LD, Segerstrom  SC, Boehm  JK.  Positive psychological functioning and the biology of health.  Soc Personal Psychol Compass. 2015;9:645-660. doi:10.1111/spc3.12224Google Scholar
52.
Peters  ML, Flink  IK, Boersma  K, Linton  SJ.  Manipulating optimism: can imaging a best possible self be used to increase future expectancies ?  J Posit Psychol. 2010;5(3):204-211. doi:10.1080/17439761003790963Google Scholar
53.
Meevissen  YM, Peters  ML, Alberts  HJ.  Become more optimistic by imagining a best possible self: effects of a two week intervention.  J Behav Ther Exp Psychiatry. 2011;42(3):371-378. doi:10.1016/j.jbtep.2011.02.012PubMedGoogle Scholar
54.
Murphy  SE, Clare O’Donoghue  M, Drazich  EH, Blackwell  SE, Christina Nobre  A, Holmes  EA.  Imagining a brighter future: the effect of positive imagery training on mood, prospective mental imagery and emotional bias in older adults.  Psychiatry Res. 2015;230(1):36-43. doi:10.1016/j.psychres.2015.07.059PubMedGoogle Scholar
55.
Malouff  JM, Schutte  NS.  Can psychological interventions increase optimism? a meta-analysis.  J Posit Psychol. 2017;12(6):594-604. doi:10.1080/17439760.2016.1221122Google Scholar
56.
Brewin  CR, Andrews  B, Valentine  JD.  Meta-analysis of risk factors for posttraumatic stress disorder in trauma-exposed adults.  J Consult Clin Psychol. 2000;68(5):748-766. doi:10.1037/0022-006X.68.5.748PubMedGoogle Scholar
57.
Ozer  EJ, Best  SR, Lipsey  TL, Weiss  DS.  Predictors of posttraumatic stress disorder and symptoms in adults: a meta-analysis.  Psychol Bull. 2003;129(1):52-73. doi:10.1037/0033-2909.129.1.52PubMedGoogle Scholar
58.
Smith  TC, Ryan  MA, Wingard  DL, Slymen  DJ, Sallis  JF, Kritz-Silverstein  D; Millennium Cohort Study Team.  New onset and persistent symptoms of post-traumatic stress disorder self reported after deployment and combat exposures: prospective population based US military cohort study.  BMJ. 2008;336(7640):366-371. doi:10.1136/bmj.39430.638241.AEPubMedGoogle Scholar
59.
Campbell  DG, Felker  BL, Liu  CF,  et al.  Prevalence of depression-PTSD comorbidity: implications for clinical practice guidelines and primary care–based interventions.  J Gen Intern Med. 2007;22(6):711-718. doi:10.1007/s11606-006-0101-4PubMedGoogle Scholar
60.
Kroenke  K, Spitzer  RL, Williams  JB, Monahan  PO, Löwe  B.  Anxiety disorders in primary care: prevalence, impairment, comorbidity, and detection.  Ann Intern Med. 2007;146(5):317-325. doi:10.7326/0003-4819-146-5-200703060-00004PubMedGoogle Scholar
61.
Wanklyn  SG, Pukay-Martin  ND, Belus  JM, St Cyr  K, Girard  TA, Monson  CM.  Trauma types as differential predictors of posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and their comorbidity.  Can J Behav Sci. 2016;48(4):296-305. Accessed November 13, 2018. doi:10.1037/cbs0000056Google Scholar
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    2 Comments for this article
    New ways to prevent pain?
    Frederick Rivara, MD | University of Washingtonn
    What I found intriguing about this study is the potential to actually prevent pain by pre-deployment interventions. Is this something that should/could be done with patients scheduled for elective surgery like joint replacement?
    CONFLICT OF INTEREST: Editor in Chief, JAMA Network Open
    A role for optimism in the peri-operative setting.
    Afton Hassett, Psy.D. | University of Michigan, Department of Anesthesiology
    Thank you for your comments, Dr. Rivara. The data supporting an important role for optimism in pain are compelling. As such, we are in the process of refining an app delivered resilience-enhancing intervention to address pre-operative anxiety (improve optimism). The goal is to create a scalable intervention that can be used by just about any patient preparing to undergo surgery. Identifying modifiable factors and related interventions to improve post-surgical pain and opioid use is a key objective of our research.
    CONFLICT OF INTEREST: None Reported
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    Citations 0
    Original Investigation
    Psychiatry
    February 8, 2019

    Association Between Predeployment Optimism and Onset of Postdeployment Pain in US Army Soldiers

    Author Affiliations
    • 1Chronic Pain and Fatigue Research Center, University of Michigan, Ann Arbor
    • 2Positive Psychology Center, University of Pennsylvania, Philadelphia
    • 3Research Facilitation Laboratory/Army Analytics Group, Monterey, California
    JAMA Netw Open. 2019;2(2):e188076. doi:10.1001/jamanetworkopen.2018.8076
    Key Points español 中文 (chinese)

    Question  Are higher levels of predeployment optimism among US Army soldiers associated with fewer reports of new pain after deployment?

    Findings  Among 20 734 US Army soldiers in this longitudinal cohort study, optimism was associated with 11% lower odds of reporting new postdeployment pain, even while adjusting for demographic, military, and combat factors, including traumatic experiences and combat injury. In addition, 37.3% of soldiers reported pain in at least 1 new area of the body after deployment.

    Meaning  The findings suggest that soldiers with low levels of predeployment optimism may be at greater risk of developing new postdeployment pain and may benefit from scalable interventions designed to increase optimism.

    Abstract

    Importance  Pain after deployment is a major health care concern. While risk factors have been previously studied, few studies have explored protective factors.

    Objective  To examine the prospective association between predeployment optimism and the onset of new pain after deployment in US Army soldiers.

    Design, Setting, and Participants  This prospective longitudinal cohort study examined US Army soldiers (active duty, Reserve, and National Guard) who deployed to Afghanistan or Iraq between February 12, 2010, and August 29, 2014, and completed the necessary psychological and health assessments before and after deployment. Analyses were performed in the Person-Event Data Environment between July 2016 and November 2018. This study relied exclusively on existing, secondary Army data. Of the 413 763 Army soldiers who met the specified deployment criteria, 385 925 soldiers were missing 1 or more of the required assessment forms. Of the remaining 27 838 soldiers who were examined for eligibility, 7104 soldiers were excluded because of preexisting back pain, joint pain, or frequent headaches. These exclusions resulted in a final analytic sample of 20 734 eligible soldiers.

    Main Outcomes and Measures  This study examined new reports of pain after deployment, including new back pain, joint pain, and frequent headaches.

    Results  Among 20 734 US Army soldiers (87.8% male; mean [SD] age, 29.06 [8.42] years), 37.3% reported pain in at least 1 new area of the body after deployment: 25.3% reported new back pain, 23.1% reported new joint pain, and 12.1% reported new frequent headaches. As a continuous measure, each 1-U increase in optimism was associated with 11% lower odds of reporting any new pain after deployment, even while adjusting for demographic, military, and combat factors (odds ratio, 0.89; 95% CI, 0.86-0.93). Tertile analyses revealed that compared with soldiers with high optimism (lowest odds of new pain) soldiers with low optimism had 35% greater odds of reporting new pain in any of the 3 sites evaluated (odds ratio, 1.35; 95% CI, 1.21-1.50). In addition, a larger increase in risk of new pain was observed when comparing the moderate-optimism and low-optimism groups rather than the high-optimism and moderate-optimism groups.

    Conclusions and Relevance  Higher levels of optimism were associated with lower odds of reporting new pain after deployment, over and above other common determinants of pain, including demographic and military characteristics and combat experiences. Soldiers with low levels of optimism before deployment could benefit from programs geared toward enhancing optimism.

    Introduction

    Pain affects more Americans than coronary heart disease, diabetes, and cancer combined, at an estimated cost of $635 billion per year.1 Yet, the consequences of chronic musculoskeletal pain may be even more profoundly experienced in military personnel after deployment.2 For example, military musculoskeletal injuries result in more than 1 million medical encounters each year, and musculoskeletal and connective tissue disorders are the most common reason for medical evacuation of deployed personnel.2,3

    Studies4-8 of veterans who served in Operation Enduring Freedom, Operation Iraqi Freedom, or Operation New Dawn have shown that from 40% to more than 80% report experiencing chronic pain after deployment. More than half of these soldiers describe pain that is moderate to severe6,8 occurring predominantly in the back, legs, shoulders, neck, and head.5,7 Such pain is frequently reported as lasting longer than 1 year, with more than half experiencing pain almost every day, if not constantly.6 Chronic pain in veterans is associated with other significant problems, such as functional disability, vocational limitations, family discord, greater health care use, traumatic brain injury, and psychiatric comorbidities, including posttraumatic stress disorder (PTSD), major depressive disorder, and substance abuse that includes opioid misuse.5,8-13

    Determining who might be at risk for chronic pain after deployment is essential. Previous studies have shown that in soldiers deployed to Afghanistan and Iraq the following characteristics are associated with postdeployment pain: older age (>30 years),6 being married or previously married,6 exposure to combat6,14 (especially injury during combat6), duty involving heavy physical labor,6 and PTSD and other psychiatric conditions.6,15 Demographic and combat factors are rarely modifiable, and PTSD and other psychiatric comorbidities tend to be the sequelae of deployment16 rather than useful predeployment determinants of the development of pain. By reframing the question to instead assess what potentially modifiable predeployment characteristics are associated with fewer instances of postdeployment pain, new targets for treatment may be identified.

    Although traumatic deployment events experienced during combat often precede PTSD,17,18 depression and substance abuse,19,20 and reports of postdeployment physical symptoms, including pain,21 these stressful experiences do not always result in negative outcomes. Many individuals are resilient to the potentially deleterious effects of combat, despite negative exposures. Therefore, it is important to understand what modifiable factors protect these soldiers from persistent negative outcomes following deployment, such as the development of chronic pain. One promising protective factor to explore is optimism. Optimism has been found to be a significant determinant of a wide range of positive physical health outcomes,22-24 including decreased pain sensitivity,25 enhanced conditioned pain modulation,26 lower risk for the development of chronic postsurgical pain,27 and better overall quality of life in adults and children with chronic pain.28 Among active duty soldiers, greater baseline levels of optimism have recently been linked to lower odds of being diagnosed as having PTSD, depression, anxiety, and adjustment disorders over a 2-year follow-up period.29

    Much of the previous research evaluating postdeployment health concerns has been limited by the use of cross-sectional data from small studies of treatment-seeking veterans. Herein, the Person-Event Data Environment, a secure and comprehensive Army cloud-based data repository and analysis platform,30,31 was used to explore the overall prevalence of postdeployment pain and to investigate optimism as a determinant of the onset of new postdeployment pain in a robust sample of soldiers. Therefore, the objectives of this study were (1) to evaluate the incidence of new postdeployment pain in a large sample of soldiers who served in Operation Enduring Freedom, Operation Iraqi Freedom, or Operation New Dawn and (2) to assess whether having high levels of optimism before deployment is associated with a decreased likelihood of reporting new pain after deployment. We hypothesized that optimism would buffer the often deleterious effects of deployment and be related to decreased odds of reporting new pain, accounting for combat and other deployment experiences.

    Methods

    This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guidelines. The study examined a subset of US Army active duty, Reserve, and National Guard soldiers who deployed to Afghanistan or Iraq between February 12, 2010, and August 29, 2014, for more than 1 day and no longer than 15 months. Additional study inclusion criteria were as follows: (1) they completed the Global Assessment Tool, a self-report questionnaire assessing psychosocial functioning taken annually by soldiers,32,33 in the year before their deployment (and indicated through an electronic “opt-in” procedure that their responses could be used for research purposes and linked to other data sources); (2) they completed Periodic Health Assessments in the year before their deployment and in the 15 months after their deployment; and (3) they completed the Post-Deployment Health Assessment in the month after their deployment. The University of Pennsylvania Institutional Review Board and a Department of Defense Human Research Protection Official reviewed and approved this study.

    Measures
    Optimism

    Four optimism items from the Global Assessment Tool, adapted from the revised Life Orientation Test,34 were asked on a 5-point Likert-type scale ranging from 1 (strongly disagree) to 5 (strongly agree). Items included the following: “In uncertain times, I usually expect the best”; “I rarely count on good things happening to me” (reverse scored); “Overall, I expect more good things to happen to me than bad”; and “If something can go wrong for me, it will” (reverse scored). Internal consistency was acceptable (α = .72). Continuous optimism represented the mean of the 4 items. In addition, soldiers were grouped into the following optimism tertiles: low (1.00-2.75), moderate (3.00-3.75), and high (4.00-5.00). Because of the distribution of optimism scores and an interest in ensuring that the low group actually reflected low levels of optimism, the low group contained a smaller percentage of the sample (8.0%) compared with the moderate (39.9%) and high (52.1%) groups.

    New Pain

    Pain reports were culled from soldiers’ postdeployment Periodic Health Assessment. The items asked “Do you or have you ever had [with separate responses for back pain, joint pain, and frequent headaches]” (yes or no)? We also created a composite measure that reflected any new back, joint, or headache pain (yes or no).

    Combat Measures

    Combat intensity assessed the occurrence (yes or no) of the following 5 potentially traumatic events during deployment: encountered dead bodies or saw people killed or wounded, felt in great danger of being killed, engaged in direct combat involving discharging a weapon, experienced a blast or explosion, and experienced a vehicular crash. Responses were summed, with higher scores indicating reporting more combat stressors. Combat injury (single item) assessed whether a soldier reported being wounded, injured, assaulted, or otherwise hurt during his or her deployment (yes or no). Combat intensity and combat injury, which were assessed on the Post-Deployment Health Assessment, were thought to serve as surrogates for PTSD and other psychiatric comorbidities and were expected to be strongly associated with greater odds of reporting new postdeployment pain.

    Health Measures

    Baseline chronic pain was culled from soldiers’ predeployment Periodic Health Assessment. Soldiers reported whether they currently had or had ever had chronic pain (yes or no). We adjusted for chronic pain at baseline because having an existing pain condition has long been associated with an increased likelihood of developing more painful conditions.35-37 Because smoking has been identified as a unique risk factor in chronic pain,38,39 nicotine status, which was obtained from soldiers’ predeployment Periodic Health Assessment, was included to capture whether soldiers reported smoking tobacco products, dipping, or chewing (yes or no).

    Demographic and Military Characteristics

    Demographic and military characteristics were obtained from Defense Manpower Data Center administrative records. Covariates included age (scaled in decades), sex (male vs female), race/ethnicity (non-Hispanic white vs other), marital status (married vs not married), educational attainment (up through high school vs more than high school), branch (active duty, Reserve, or National Guard), rank (officer vs enlisted), whether a soldier had previously deployed (yes vs no), and deployment location (Afghanistan or Iraq). Demographic characteristics (eg, race/ethnicity) were initially obtained through self-report, whereas military characteristics (eg, rank) were obtained through official records. Self-reported race/ethnicity information was dichotomized for the present analyses and was included to account for commonly observed differences.40,41

    Statistical Analysis

    Analyses were performed in the Person-Event Data Environment between July 2016 and November 2018 using SAS Enterprise Guide (version 7.12; SAS Institute Inc). This study relied exclusively on existing, secondary Army data. We used binomial logistic regression to examine the association between continuous optimism and new pain (separate models examined any pain, back pain, joint pain, and frequent headaches), adjusting for covariates, which were entered into the model simultaneously. We repeated these analyses, replacing continuous optimism with optimism tertiles. To obtain all 3 pairwise comparisons, we first modeled high optimism as the reference group and then moderate optimism as the reference group. Multicollinearity diagnostics did not detect any problems.

    Post hoc analyses tested for optimism by sex interactions and, separately, optimism by marital status interactions. Statistically significant interactions (2-sided P < .05) were followed up with stratified analyses to clarify the nature of the interaction.

    To test for possible bias, we examined whether there were any systematic differences between soldiers who did and did not report back, joint, or headache pain at baseline (ie, excluded vs included). In addition, we compared soldiers in the analytic sample with soldiers who were excluded because of missing assessments.

    Results
    Participants

    Of the 413 763 Army active duty, Reserve, and National Guard soldiers who deployed to Afghanistan or Iraq between February 12, 2010, and August 29, 2014 (>1 day and ≤15 months), 385 925 soldiers (93.3%) were missing 1 or more of the required assessment forms. Of the remaining 27 838 soldiers who were examined for eligibility, 7104 soldiers (25.5%) were excluded because they reported predeployment back pain, joint pain, or frequent headaches. These exclusions yielded a final analytic sample of 20 734 eligible soldiers. Figure 1 shows a flowchart of the sample selection in this study.

    Anticipating New Postdeployment Pain

    Among 20 734 US Army soldiers (87.8% male; mean [SD] age, 29.06 [8.42] years), 37.3% reported pain in at least 1 new area of the body after deployment: 25.3% reported new back pain, 23.1% reported new joint pain, and 12.1% reported new frequent headaches. The results of McNemar tests indicated that new back pain and joint pain were reported more frequently than new frequent headaches. Approximately half of the sample (52.1%) reported high optimism, 39.9% reported moderate optimism, and 8.0% reported low optimism. Additionally, both stressful combat experiences (46.4%) and combat injuries (20.2%) were fairly common. A summary of sample characteristics is listed in Table 1.

    As a continuous measure, each 1-U increase in optimism was associated with 11% lower odds of reporting any new pain after deployment (odds ratio [OR], 0.89; 95% CI, 0.86-0.93) (Table 2). Examining the pain areas separately revealed that optimism was associated with 8% lower odds of developing new back pain (OR, 0.92; 95% CI, 0.88-0.96) and 8% lower odds of developing new joint pain (OR, 0.92; 95% CI, 0.88-0.96). However, we did not observe a significant statistical association between optimism and new frequent headaches after deployment (OR, 0.96; 95% CI, 0.91-1.02).

    We next modeled optimism tertiles (Table 3) and found that compared with soldiers with high optimism (lowest odds of new pain) soldiers with low optimism had the following characteristics: 35% greater odds of any new pain (OR, 1.35; 95% CI, 1.21-1.50), 30% greater odds of new back pain (OR, 1.30; 95% CI, 1.16-1.46), 21% greater odds of new joint pain (OR, 1.21; 95% CI, 1.07-1.38), and 18% greater odds of new frequent headaches (OR, 1.18; 95% CI, 1.01-1.38). In addition, we observed a larger increase in odds of new pain when comparing the moderate-optimism and low-optimism groups rather than the high-optimism and moderate-optimism groups.

    Associations between demographic characteristics and new pain are summarized in Table 2 and Table 3. Being older and being married were associated with increased odds of reporting new postdeployment pain. Women were more likely to report any new pain or new frequent headaches; for women and men, reporting chronic pain at baseline was associated with greater odds of reporting any new pain, new back pain, or new joint pain after deployment. In addition, being injured while deployed and reporting stressful combat experiences were each associated with greater odds of reporting new pain after deployment. In contrast, being an officer (vs an enlisted soldier) and deploying to Iraq (vs Afghanistan) were each associated with reduced odds of reporting new pain after deployment. Of the soldiers who reported new pain in all 3 areas, a disproportionate number (63.3%) were National Guard soldiers compared with active duty (19.7%) and Reserve (17.0%) soldiers.

    Tests of Moderation

    We also tested interactions between optimism and sex and, separately, between optimism and marital status. We did not observe any statistically significant interactions between optimism and sex or between optimism and marital status in relation to any new pain, new back pain, or new joint pain. However, we observed a statistically significant interaction between optimism and marital status in association with new frequent headaches (OR, 0.85; 95% CI, 0.76-0.95). Stratified analyses (Figure 2) revealed that greater optimism was associated with lower odds of reporting frequent headaches after deployment among married soldiers (OR, 0.89; 95% CI, 0.83-0.97) but not unmarried soldiers (OR, 1.05; 95% CI, 0.96-1.14).

    Sample Generalization

    Compared with soldiers in the analytic sample (N = 20 734), soldiers excluded for reporting predeployment back pain, joint pain, or frequent headaches (n = 7104) were slightly less optimistic (3.87 vs 3.72, respectively) and older (29.1 vs 33.8 years, respectively). Soldiers who reported predeployment pain were more likely to be married (70.4% vs 50.5%), have more than a high school education (42.1% vs 32.3%), report predeployment chronic pain (16.5% vs 0.7%), be active duty (58.5% vs 36.1%), or have previously deployed (70.7% vs 38.7%) compared with soldiers in the analytic sample. In addition, soldiers with predeployment pain were less likely than those in the analytic sample to be in the National Guard (24.7% vs 42.7%) or be enlisted (79.9% vs 85.7%). All other demographic differences were negligible (<5% difference). In addition, a comparison between the analytic sample and the sample excluded because of missing assessments revealed that, aside from differences in branch (active duty soldiers were more likely to be missing assessments), the 2 groups were fairly comparable.

    Discussion

    Few studies have assessed instances of new pain in military personnel after deployment. In the present study of 20 734 Army soldiers who deployed to Afghanistan or Iraq, 37.3% reported experiencing at least 1 new area of pain after deployment, with new back pain (25.3%) and new joint pain (23.1%) described more often than new frequent headaches (12.1%). A major strength of this study was the large sample size, which enabled us to obtain accurate point estimates and narrow 95% CIs. In addition, although only a subset of the population completed the health assessments required for inclusion in this study, the study sample was fairly representative of the 2010 Army active duty population42 (sample vs population): officers (14.4% vs 16.8%), female (12.2% vs 13.4%), 25 years or younger (45.0% vs 41.2%), and married (50.5% vs 58.7%).

    In regard to optimism, the soldiers were remarkably optimistic, with 52.1% reporting high levels of optimism before deployment. Furthermore, greater predeployment optimism was associated with significantly lower odds of reporting new postdeployment pain (particularly any, back, and joint pain), even while adjusting for other important pain-related factors, such as combat intensity, combat injuries, baseline chronic pain, nicotine use, and key demographic and military characteristics. As such, every 1-U increase in optimism was independently associated with 11% lower odds of reporting new pain in any of the 3 bodily areas evaluated. Moreover, the least optimistic soldiers had 35% greater odds of reporting a new instance of pain compared with those with the highest levels of optimism. The difference between the soldiers with moderate levels of optimism and those with the highest levels was not, for the most part, statistically significant, suggesting that extremely high levels of optimism may not be necessary to experience benefit.

    Similar to prior research,6 we found that being older and being married were associated with reporting pain after deployment. Furthermore, we observed a number of associations between military characteristics and odds of reporting new postdeployment pain. For example, enlisted soldiers were more likely to report new postdeployment pain compared with officers. This may in part be because in the combat theater, senior officers (and some noncommissioned officers) are typically responsible for strategic planning, whereas enlisted soldiers are typically responsible for riskier and more physically demanding tasks (eg, combat patrols, convoy operations, and ensuring that routes are clear of improvised explosive devices). In addition, compared with active duty soldiers, National Guard soldiers had a higher odds of reporting new postdeployment back pain, joint pain, or frequent headaches, whereas Reserve soldiers had lower odds of reporting new pain in these areas. This may in part be because National Guard soldiers tend to engage in direct combat, whereas Reserve soldiers tend to perform combat support and service duties (less risky assignments), and active duty soldiers serve in a wide variety of roles, including direct combat, combat support, and combat service.

    This study also revealed that soldiers who deployed to Iraq had a reduced odds of reporting new pain relative to soldiers who deployed to Afghanistan. During the study deployment time frame (February 12, 2010, to August 29, 2014), walking patrols were fairly common. Poor infrastructure in Afghanistan (eg, lack of good roads and walking paths), coupled with extreme temperatures, may explain in part the more frequent new pain reported by soldiers who deployed to Afghanistan compared with Iraq.

    In regard to combat experiences, we found that combat injuries and stressful combat events were common (20.2% and 46.4%, respectively) and associated with new postdeployment pain. That combat experiences were determinants of new pain has been previously shown43-45 and is intuitive (physical injury and acute pain can transition into chronic pain), while PTSD and other psychiatric comorbidities are common correlates of pain.46 Herein, combat experiences were used as a surrogate for PTSD and other psychiatric comorbidities because these traumatic experiences typically precede the manifestation of psychiatric sequelae.16 Despite the robust association between the onset of new postdeployment pain and key demographic, military, and combat experiences, predeployment optimism remained significantly associated with new postdeployment pain.

    No studies to date have explored the prospective association between optimism and postdeployment pain in military personnel. Although data from the Global Assessment Tool have been shown to differentiate Army Rangers from non-Rangers (Rangers demonstrate greater optimism, engagement, and organizational trust and lower levels of depression, catastrophizing, and loneliness),47 the postdeployment associations with optimism have yet to be reported. Others have shown that optimism is associated with better health outcomes in diverse patient populations, including cardiovascular disease,23 diabetes,48 and even mortality from multiple causes.49 Therefore, the protective association between optimism and pain is not surprising given that high optimism has been associated with decreased pain and better quality of life in civilian populations when pain is present.27,28 Herein, we add the protective association between optimism and the development of pain in soldiers after deployment.

    Optimism is generally considered a trait, although it has been estimated that optimism is only about 25% heritable.50 Therefore, optimism can be learned and is thus a modifiable factor.51 Previous studies52-54 have shown that straightforward interventions can result in higher levels of optimism. For example, interventions can include imagining and writing about a vision of one’s best possible self (ie, the person we would like to be)52,53 or imagery training to increase positive appraisals of ambiguous social situations as opposed to anticipating the worst possible outcome.54 Furthermore, interventions that promote the expression of gratitude and teach meditation and mindfulness practices, as well as more structured interventions like cognitive behavior therapy that more directly challenge catastrophic thinking, can promote optimism.55

    Limitations

    This study has some limitations. First, the assessment of new areas of pain was limited by the number of areas that were assessed both before and after deployment. The 3 areas selected are those where pain is commonly observed but by no means were exhaustive; therefore, our rates of new pain may underestimate the true number of soldiers with new postdeployment pain. Second, neither the duration nor the intensity of pain was assessed; therefore, the overall influence, chronicity, and severity of the pain are not known. Third, this study only examined reports of new pain within 15 months of returning from deployment. The extent to which optimism is associated with pain over a longer follow-up remains unknown. Fourth, as with all research, we were only able to examine soldiers who completed the necessary assessments and allowed their responses to be used for research purposes. However, the study sample was representative of the 2010 Army active duty population.42 Fifth, we did not adjust for psychiatric disorders, such as PTSD, in the present analyses. However, we adjusted for potentially traumatic experiences during deployment, which have consistently been linked to PTSD,56-58 along with comorbid psychiatric disorders, such as depression and anxiety disorders.59-61

    Conclusions

    Reducing instances of new pain after deployment is critical because 37.3% of soldiers herein reported at least 1 new area of pain. Over and above other common determinants of pain after deployment, including demographic and military characteristics and combat experiences, higher levels of optimism were associated with lower odds of reporting new pain. Data from Army psychological assessments like the Global Assessment Tool could be used to identify soldiers with low levels of optimism who may benefit from programs geared toward enhancing optimism. In current and future conflicts, these strategies could help diminish the consequences of pain, one of the most common and costly outcomes of deployment.

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    Article Information

    Accepted for Publication: December 18, 2018.

    Published: February 8, 2019. doi:10.1001/jamanetworkopen.2018.8076

    Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2019 Hassett AL et al. JAMA Network Open.

    Corresponding Author: Afton L. Hassett, PsyD, Chronic Pain and Fatigue Research Center, University of Michigan, 24 Frank Lloyd Wright Dr, Lobby M, Ann Arbor, MI 48106 (afton@med.umich.edu).

    Author Contributions: Dr Fisher and Ms Kelley had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

    Concept and design: Hassett, Fisher, Vie, Seligman.

    Acquisition, analysis, or interpretation of data: Hassett, Fisher, Vie, Kelley, Clauw.

    Drafting of the manuscript: Hassett, Fisher, Vie, Kelley.

    Critical revision of the manuscript for important intellectual content: Hassett, Vie, Clauw, Seligman.

    Statistical analysis: Fisher, Vie, Kelley.

    Obtained funding: Clauw, Seligman.

    Administrative, technical, or material support: Hassett, Fisher, Kelley, Clauw.

    Supervision: Hassett, Vie.

    Conflict of Interest Disclosures: Dr Hassett reported receiving personal fees and consulting fees from AbbVie. Dr Clauw reported receiving consulting fees from Pfizer, Tonix, Aptinyx, Daiichi Sankyo, Samumed, Intec Pharma, Eli Lilly & Co, Zynerba, Williams & Connolly LLP, and Therevance and reported receiving research support from Pfizer and Aptinyx. Dr Seligman reported that the University of Pennsylvania has a proprietary interest in Master Resilience Training, which is the backbone of the US Army’s Comprehensive Soldier Fitness program; reported that the University of Pennsylvania also licenses such resilience and positive psychology training programs to private companies and that he receives a nominal fee from the university for some of these; and reported often being paid to give speeches in which he mentions resilience and resilience training. No other disclosures were reported.

    Funding/Support: This publication stems from a military-civilian collaboration, supported in part by the Robert Wood Johnson Foundation through a grant to the Positive Psychology Center of the University of Pennsylvania (Dr Seligman, principal investigator, and Rhonda Cornum, MD, PhD, co–principal investigator).

    Role of the Funder/Sponsor: The funding source had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

    Disclaimer: The US Department of Defense does not exercise any editorial, security, or other control over the information in this article. The authors assume responsibility for the veracity, accuracy, and source documentation of the material, including no use of classified material and conformity to copyright and usage permissions. The views expressed in this article are those of the authors and do not necessarily represent the official policy of the Department of the Army, Department of Defense, or the US government.

    Additional Contributions: Les McFarling, PhD, and Kristin Saboe, PhD, from the Army Resiliency Directorate, assisted with acquiring Global Assessment Tool data. Douglas Bonett, PhD, from the University of California, Santa Cruz, provided statistical guidance. Jason Manley, BS, Phillip Silva, MBA, MS, and Samuel Taylor, MS, from the Research Facilitation Laboratory/Army Analytics Group, assisted with contextualizing the military characteristics under investigation. We acknowledge the significant support provided to this project by the men and women of the Office of the Deputy Under Secretary of the Army, the Army Analytics Group, and the Research Facilitation Laboratory. None of the listed contributors received compensation.

    References
    1.
    Institute of Medicine.  Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research. Washington, DC: National Academy of Sciences; 2011.
    2.
    US Army Public Health Center. 2017 Health of the Force. https://phc.amedd.army.mil/Periodical%20Library/2017HealthoftheForceReportWeb_Printer.pdf. Published 2017. Accessed November 13, 2018.
    3.
    Cohen  SP, Brown  C, Kurihara  C, Plunkett  A, Nguyen  C, Strassels  SA.  Diagnoses and factors associated with medical evacuation and return to duty for service members participating in Operation Iraqi Freedom or Operation Enduring Freedom: a prospective cohort study.  Lancet. 2010;375(9711):301-309. doi:10.1016/S0140-6736(09)61797-9PubMedGoogle Scholar
    4.
    Cifu  DX, Taylor  BC, Carne  WF,  et al.  Traumatic brain injury, posttraumatic stress disorder, and pain diagnoses in OIF/OEF/OND Veterans.  J Rehabil Res Dev. 2013;50(9):1169-1176. doi:10.1682/JRRD.2013.01.0006PubMedGoogle Scholar
    5.
    Lew  HL, Cifu  DX, Crowder  T, Hinds  SR.  National prevalence of traumatic brain injury, posttraumatic stress disorder, and pain diagnoses in OIF/OEF/OND Veterans from 2009 to 2011.  J Rehabil Res Dev. 2013;50(9):xi-xiv. doi:10.1682/JRRD.2013.09.0212PubMedGoogle Scholar
    6.
    Toblin  RL, Quartana  PJ, Riviere  LA, Walper  KC, Hoge  CW.  Chronic pain and opioid use in US soldiers after combat deployment.  JAMA Intern Med. 2014;174(8):1400-1401. doi:10.1001/jamainternmed.2014.2726PubMedGoogle Scholar
    7.
    Gironda  RJ, Clark  ME, Massengale  JP, Walker  RL.  Pain among veterans of Operations Enduring Freedom and Iraqi Freedom.  Pain Med. 2006;7(4):339-343. doi:10.1111/j.1526-4637.2006.00146.xPubMedGoogle Scholar
    8.
    Phillips  KM, Clark  ME, Gironda  RJ,  et al.  Pain and psychiatric comorbidities among two groups of Iraq and Afghanistan era Veterans.  J Rehabil Res Dev. 2016;53(4):413-432. doi:10.1682/JRRD.2014.05.0126PubMedGoogle Scholar
    9.
    Bosco  MA, Murphy  JL, Clark  ME.  Chronic pain and traumatic brain injury in OEF/OIF service members and Veterans.  Headache. 2013;53(9):1518-1522.PubMedGoogle Scholar
    10.
    Forman-Hoffman  VL, Peloso  PM, Black  DW, Woolson  RF, Letuchy  EM, Doebbeling  BN.  Chronic widespread pain in veterans of the first Gulf War: impact of deployment status and associated health effects.  J Pain. 2007;8(12):954-961. doi:10.1016/j.jpain.2007.07.003PubMedGoogle Scholar
    11.
    Helmer  DA, Chandler  HK, Quigley  KS, Blatt  M, Teichman  R, Lange  G.  Chronic widespread pain, mental health, and physical role function in OEF/OIF veterans.  Pain Med. 2009;10(7):1174-1182. doi:10.1111/j.1526-4637.2009.00723.xPubMedGoogle Scholar
    12.
    Lewis  JD, Wassermann  EM, Chao  W, Ramage  AE, Robin  DA, Clauw  DJ.  Central sensitization as a component of post-deployment syndrome.  NeuroRehabilitation. 2012;31(4):367-372.PubMedGoogle Scholar
    13.
    Ramirez  S, Bebarta  VS, Varney  SM, Ganem  V, Zarzabal  LA, Potter  JS.  Misuse of prescribed pain medication in a military population: a self-reported survey to assess a correlation with age, deployment, combat illnesses, or injury?  Am J Ther. 2017;24(2):e150-e156. doi:10.1097/MJT.0000000000000141PubMedGoogle Scholar
    14.
    Granado  NS, Pietrucha  A, Ryan  M,  et al.  Longitudinal assessment of self-reported recent back pain and combat deployment in the Millennium Cohort Study.  Spine (Phila Pa 1976). 2016;41(22):1754-1763. doi:10.1097/BRS.0000000000001739PubMedGoogle Scholar
    15.
    Uomoto  JM, Esselman  PC.  Traumatic brain injury and chronic pain: differential types and rates by head injury severity.  Arch Phys Med Rehabil. 1993;74(1):61-64.PubMedGoogle Scholar
    16.
    Wells  TS, LeardMann  CA, Fortuna  SO,  et al; Millennium Cohort Study Team.  A prospective study of depression following combat deployment in support of the wars in Iraq and Afghanistan.  Am J Public Health. 2010;100(1):90-99. doi:10.2105/AJPH.2008.155432PubMedGoogle Scholar
    17.
    Ramchand  R, Schell  TL, Karney  BR, Osilla  KC, Burns  RM, Caldarone  LB.  Disparate prevalence estimates of PTSD among service members who served in Iraq and Afghanistan: possible explanations.  J Trauma Stress. 2010;23(1):59-68.PubMedGoogle Scholar
    18.
    Vasterling  JJ, Proctor  SP, Friedman  MJ,  et al.  PTSD symptom increases in Iraq-deployed soldiers: comparison with nondeployed soldiers and associations with baseline symptoms, deployment experiences, and postdeployment stress.  J Trauma Stress. 2010;23(1):41-51.PubMedGoogle Scholar
    19.
    Quartana  PJ, Wilk  JE, Balkin  TJ, Hoge  CW.  Indirect associations of combat exposure with post-deployment physical symptoms in U.S. soldiers: roles of post-traumatic stress disorder, depression and insomnia.  J Psychosom Res. 2015;78(5):478-483. doi:10.1016/j.jpsychores.2014.11.017PubMedGoogle Scholar
    20.
    Hoopsick  RA, Vest  BM, Homish  DL, Homish  GG.  Combat exposure, emotional and physical role limitations, and substance use among male United States Army Reserve and National Guard soldiers.  Qual Life Res. 2018;27(1):137-147. doi:10.1007/s11136-017-1706-2PubMedGoogle Scholar
    21.
    Finan  PH, Quartana  PJ, Smith  MT.  Positive and negative affect dimensions in chronic knee osteoarthritis: effects on clinical and laboratory pain.  Psychosom Med. 2013;75(5):463-470. doi:10.1097/PSY.0b013e31828ef1d6PubMedGoogle Scholar
    22.
    Rasmussen  HN, Scheier  MF, Greenhouse  JB.  Optimism and physical health: a meta-analytic review.  Ann Behav Med. 2009;37(3):239-256. doi:10.1007/s12160-009-9111-xPubMedGoogle Scholar
    23.
    DuBois  CM, Lopez  OV, Beale  EE, Healy  BC, Boehm  JK, Huffman  JC.  Relationships between positive psychological constructs and health outcomes in patients with cardiovascular disease: a systematic review.  Int J Cardiol. 2015;195:265-280. doi:10.1016/j.ijcard.2015.05.121PubMedGoogle Scholar
    24.
    Schiavon  CC, Marchetti  E, Gurgel  LG, Busnello  FM, Reppold  CT.  Optimism and hope in chronic disease: a systematic review.  Front Psychol. 2017;7:2022. doi:10.3389/fpsyg.2016.02022PubMedGoogle Scholar
    25.
    Goodin  BR, Glover  TL, Sotolongo  A,  et al.  The association of greater dispositional optimism with less endogenous pain facilitation is indirectly transmitted through lower levels of pain catastrophizing.  J Pain. 2013;14(2):126-135. doi:10.1016/j.jpain.2012.10.007PubMedGoogle Scholar
    26.
    Goodin  BR, Kronfli  T, King  CD, Glover  TL, Sibille  K, Fillingim  RB.  Testing the relation between dispositional optimism and conditioned pain modulation: does ethnicity matter?  J Behav Med. 2013;36(2):165-174. doi:10.1007/s10865-012-9411-7PubMedGoogle Scholar
    27.
    Sobol-Kwapinska  M, Bąbel  P, Plotek  W, Stelcer  B.  Psychological correlates of acute postsurgical pain: a systematic review and meta-analysis.  Eur J Pain. 2016;20(10):1573-1586. doi:10.1002/ejp.886PubMedGoogle Scholar
    28.
    Goodin  BR, Bulls  HW.  Optimism and the experience of pain: benefits of seeing the glass as half full.  Curr Pain Headache Rep. 2013;17(5):329. doi:10.1007/s11916-013-0329-8PubMedGoogle Scholar
    29.
    Shrestha  A, Cornum  BGR, Vie  LL, Scheier  LM, Lester  MAJPB, Seligman  MEP.  Protective effects of psychological strengths against psychiatric disorders among soldiers.  Mil Med. 2018;183(suppl_1):386-395. doi:10.1093/milmed/usx189PubMedGoogle Scholar
    30.
    Vie  LL, Griffith  KN, Scheier  LM, Lester  PB, Seligman  ME.  The Person-Event Data Environment: leveraging big data for studies of psychological strengths in soldiers.  Front Psychol. 2013;4:934. doi:10.3389/fpsyg.2013.00934PubMedGoogle Scholar
    31.
    Vie  LL, Scheier  LM, Lester  PB, Ho  TE, Labarthe  DR, Seligman  ME.  The U.S. Army Person-Event Data Environment: a military-civilian big data enterprise.  Big Data. 2015;3(2):67-79. doi:10.1089/big.2014.0055PubMedGoogle Scholar
    32.
    Peterson  C, Park  N, Castro  CA.  Assessment for the U.S. Army Comprehensive Soldier Fitness program: the Global Assessment Tool.  Am Psychol. 2011;66(1):10-18. doi:10.1037/a0021658PubMedGoogle Scholar
    33.
    Vie  LL, Scheier  LM, Lester  PB, Seligman  MEP.  Initial validation of the U.S. Army Global Assessment Tool.  Mil Psychol. 2016;28(6):468-487. </jrn> doi:10.1037/mil0000141Google Scholar
    34.
    Scheier  MF, Carver  CS, Bridges  MW.  Distinguishing optimism from neuroticism (and trait anxiety, self-mastery, and self-esteem): a reevaluation of the Life Orientation Test.  J Pers Soc Psychol. 1994;67(6):1063-1078. doi:10.1037/0022-3514.67.6.1063PubMedGoogle Scholar
    35.
    Clauw  DJ.  Fibromyalgia: a clinical review.  JAMA. 2014;311(15):1547-1555. doi:10.1001/jama.2014.3266PubMedGoogle Scholar
    36.
    Aaron  LA, Buchwald  D.  A review of the evidence for overlap among unexplained clinical conditions.  Ann Intern Med. 2001;134(9, pt 2):868-881. doi:10.7326/0003-4819-134-9_Part_2-200105011-00011PubMedGoogle Scholar
    37.
    Hudson  JI, Pope  HG.  The concept of affective spectrum disorder: relationship to fibromyalgia and other syndromes of chronic fatigue and chronic muscle pain.  Baillieres Clin Rheumatol. 1994;8(4):839-856. doi:10.1016/S0950-3579(05)80051-2PubMedGoogle Scholar
    38.
    Goesling  J, Brummett  CM, Meraj  TS, Moser  SE, Hassett  AL, Ditre  JW.  Associations between pain, current tobacco smoking, depression, and fibromyalgia status among treatment-seeking chronic pain patients.  Pain Med. 2015;16(7):1433-1442. doi:10.1111/pme.12747PubMedGoogle Scholar
    39.
    Shiri  R, Karppinen  J, Leino-Arjas  P, Solovieva  S, Viikari-Juntura  E.  The association between smoking and low back pain: a meta-analysis.  Am J Med. 2010;123(1):87.e7-87.e35. doi:10.1016/j.amjmed.2009.05.028PubMedGoogle Scholar
    40.
    Hardt  J, Jacobsen  C, Goldberg  J, Nickel  R, Buchwald  D.  Prevalence of chronic pain in a representative sample in the United States.  Pain Med. 2008;9(7):803-812. doi:10.1111/j.1526-4637.2008.00425.xPubMedGoogle Scholar
    41.
    Nahin  RL.  Estimates of pain prevalence and severity in adults: United States, 2012.  J Pain. 2015;16(8):769-780. doi:10.1016/j.jpain.2015.05.002PubMedGoogle Scholar
    42.
    US Department of Defense. Demographics 2010: Profile of the Military Community. http://download.militaryonesource.mil/12038/MOS/Reports/2010-Demographics-Report.pdf. Published 2010. Accessed December 10, 2018.
    43.
    McLean  SA, Clauw  DJ, Abelson  JL, Liberzon  I.  The development of persistent pain and psychological morbidity after motor vehicle collision: integrating the potential role of stress response systems into a biopsychosocial model.  Psychosom Med. 2005;67(5):783-790. doi:10.1097/01.psy.0000181276.49204.bbPubMedGoogle Scholar
    44.
    McLean  SA, Williams  DA, Clauw  DJ.  Fibromyalgia after motor vehicle collision: evidence and implications.  Traffic Inj Prev. 2005;6(2):97-104. doi:10.1080/15389580580590931545PubMedGoogle Scholar
    45.
    Lanier  PJ, Speirs  J, Koehler  L, Bader  J, Abdelgawad  A, Waterman  BR.  Predictors of persistent pain after fixation of distal clavicle fractures in an active military population.  Orthopedics. 2018;41(1):e117-e126. doi:10.3928/01477447-20171127-02PubMedGoogle Scholar
    46.
    Fishbain  DA, Pulikal  A, Lewis  JE, Gao  J.  Chronic pain types differ in their reported prevalence of post-traumatic stress disorder (PTSD) and there is consistent evidence that chronic pain is associated with PTSD: an evidence-based structured systematic review.  Pain Med. 2017;18(4):711-735.PubMedGoogle Scholar
    47.
    Lester  PB, Harms  PD, Herian  MN, Sowden  WJ.  A force of change: Chris Peterson and the US Army’s Global Assessment Tool.  J Posit Psychol. 2015;10(1):7-16. doi:10.1080/17439760.2014.927904Google Scholar
    48.
    Puig-Perez  S, Hackett  RA, Salvador  A, Steptoe  A.  Optimism moderates psychophysiological responses to stress in older people with type 2 diabetes.  Psychophysiology. 2017;54(4):536-543. doi:10.1111/psyp.12806PubMedGoogle Scholar
    49.
    Kim  ES, Hagan  KA, Grodstein  F, DeMeo  DL, De Vivo  I, Kubzansky  LD.  Optimism and cause-specific mortality: a prospective cohort study.  Am J Epidemiol. 2017;185(1):21-29. doi:10.1093/aje/kww182PubMedGoogle Scholar
    50.
    Plomin  R, Scheier  MF, Bergeman  CS, Pedersen  NL, Nesselroade  JR, McClearn  GE.  Optimism, pessimism and mental health: a twin/adoption analysis.  Pers Individ Dif. 1992;13(8):921-930.</jrn> doi:10.1016/0191-8869(92)90009-EGoogle Scholar
    51.
    Kubzansky  LD, Segerstrom  SC, Boehm  JK.  Positive psychological functioning and the biology of health.  Soc Personal Psychol Compass. 2015;9:645-660. doi:10.1111/spc3.12224Google Scholar
    52.
    Peters  ML, Flink  IK, Boersma  K, Linton  SJ.  Manipulating optimism: can imaging a best possible self be used to increase future expectancies ?  J Posit Psychol. 2010;5(3):204-211. doi:10.1080/17439761003790963Google Scholar
    53.
    Meevissen  YM, Peters  ML, Alberts  HJ.  Become more optimistic by imagining a best possible self: effects of a two week intervention.  J Behav Ther Exp Psychiatry. 2011;42(3):371-378. doi:10.1016/j.jbtep.2011.02.012PubMedGoogle Scholar
    54.
    Murphy  SE, Clare O’Donoghue  M, Drazich  EH, Blackwell  SE, Christina Nobre  A, Holmes  EA.  Imagining a brighter future: the effect of positive imagery training on mood, prospective mental imagery and emotional bias in older adults.  Psychiatry Res. 2015;230(1):36-43. doi:10.1016/j.psychres.2015.07.059PubMedGoogle Scholar
    55.
    Malouff  JM, Schutte  NS.  Can psychological interventions increase optimism? a meta-analysis.  J Posit Psychol. 2017;12(6):594-604. doi:10.1080/17439760.2016.1221122Google Scholar
    56.
    Brewin  CR, Andrews  B, Valentine  JD.  Meta-analysis of risk factors for posttraumatic stress disorder in trauma-exposed adults.  J Consult Clin Psychol. 2000;68(5):748-766. doi:10.1037/0022-006X.68.5.748PubMedGoogle Scholar
    57.
    Ozer  EJ, Best  SR, Lipsey  TL, Weiss  DS.  Predictors of posttraumatic stress disorder and symptoms in adults: a meta-analysis.  Psychol Bull. 2003;129(1):52-73. doi:10.1037/0033-2909.129.1.52PubMedGoogle Scholar
    58.
    Smith  TC, Ryan  MA, Wingard  DL, Slymen  DJ, Sallis  JF, Kritz-Silverstein  D; Millennium Cohort Study Team.  New onset and persistent symptoms of post-traumatic stress disorder self reported after deployment and combat exposures: prospective population based US military cohort study.  BMJ. 2008;336(7640):366-371. doi:10.1136/bmj.39430.638241.AEPubMedGoogle Scholar
    59.
    Campbell  DG, Felker  BL, Liu  CF,  et al.  Prevalence of depression-PTSD comorbidity: implications for clinical practice guidelines and primary care–based interventions.  J Gen Intern Med. 2007;22(6):711-718. doi:10.1007/s11606-006-0101-4PubMedGoogle Scholar
    60.
    Kroenke  K, Spitzer  RL, Williams  JB, Monahan  PO, Löwe  B.  Anxiety disorders in primary care: prevalence, impairment, comorbidity, and detection.  Ann Intern Med. 2007;146(5):317-325. doi:10.7326/0003-4819-146-5-200703060-00004PubMedGoogle Scholar
    61.
    Wanklyn  SG, Pukay-Martin  ND, Belus  JM, St Cyr  K, Girard  TA, Monson  CM.  Trauma types as differential predictors of posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and their comorbidity.  Can J Behav Sci. 2016;48(4):296-305. Accessed November 13, 2018. doi:10.1037/cbs0000056Google Scholar
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