Intern operative volume before (2007-2011) and after (2011-2012) the duty-hour change.
Schwartz SI, Galante J, Kaji A, Dolich M, Easter D, Melcher ML, Patel K, Reeves ME, Salim A, Senagore AJ, Takanishi DM, de Virgilio C. Effect of the 16-Hour Work Limit on General Surgery Intern Operative Case VolumeA Multi-institutional Study. JAMA Surg. 2013;148(9):829–833. doi:10.1001/jamasurg.2013.2677
The 80-hour work-week limit for all residents was instituted in 2003 and studies looking at its effect have been mixed. Since the advent of the 16-hour mandate for postgraduate year 1 residents in July 2011, no data have been published regarding the effect of this additional work-hour restriction.
To determine whether the 16-hour intern work limit, implemented in July 2011, has adversely affected operative experience.
Design, Setting, and Participants
A retrospective review of categorical postgraduate year 1 Accreditation Council for Graduate Medical Education case logs from the intern class (N = 52) (with 16-hour work limit) compared with the 4 preceding years (2007-2010; N = 197) (without 16-hour work limit). A total of 249 categorical general surgery interns from 10 general surgery residency programs in the western United States were included.
Main Outcomes and Measures
Total, major, first-assistant, and defined-category case totals.
As compared with the preceding 4 years, the 2011-2012 interns recorded a 25.8% decrease in total operative cases (65.9 vs 88.8, P = .005), a 31.8% decrease in major cases (54.9 vs 80.5, P < .001), and a 46.3% decrease in first-assistant cases (11.1 vs 20.7, P = .008). There were statistically significant decreases in cases within the defined categories of abdomen, endocrine, head and neck, basic laparoscopy, complex laparoscopy, pediatrics, thoracic, and soft tissue/breast surgery in the 16-hour shift intern era, whereas there was no decrease in trauma, vascular, alimentary, endoscopy, liver, and pancreas cases.
Conclusions and Relevance
The 16-hour work limit for interns, implemented in July 2011, is associated with a significant decrease in categorical intern operative experience. If the 16-hour shift were to be extended to all postgraduate year levels, one can anticipate that additional years of training will be needed to maintain the same operative volume.
Over the past decade, 2 major changes to general surgery residency duty hours have been implemented by the Accreditation Council for Graduate Medical Education. The 80-hour work-week limit for all residents was instituted in 2003 and included a required 4 days off per 28 calendar days. More recently, a maximum shift length of 16 hours per day was mandated for all postgraduate year (PGY) 1 residents.
Several studies have looked at the effect of the 80-hour work-week reduction on resident operative volume. The outcomes were mixed. Some studies demonstrated an increase in total case volume,1 whereas others have shown decreases or no statistically significant changes in operative volume.2- 6 Other outcome measures were also analyzed in several studies—American Board of Surgery In-Service Training Examination scores, first-time American Board of Surgery certifying examination pass rates, and patient outcomes—making the 80-hour work week one of the most heavily studied—and controversial—topics of general surgery in the last 10 years.7- 9
In 2008, in response to a congressional request to study resident duty hours, the Institute of Medicine of the National Academies analyzed the deleterious effects of increased shift length.10 This report led to the Accreditation Council for Graduate Medical Education recommendation to limit the duty shift for all PGY 1 residents to 16 hours beginning in July 2011.11
Since the advent of the 16-hour mandate in July 2011, no data have been published regarding the effect of this additional work-hour restriction on PGY 1 operative experience. The goal of our multi-institutional study was to determine whether the 16-hour intern work limit has adversely affected operative experience at the PGY 1 categorical general surgery resident level.
Accreditation Council for Graduate Medical Education operative case logs for categorical interns were retrospectively reviewed for 5 consecutive academic years (2007-2008, 2008-2009, 2009-2010, 2010-2011, and 2011-2012). Ten general surgery residency programs (Harbor–University of California at Los Angeles, University of Southern California, Cedars Sinai, Stanford University, University of California at Irvine, University of California at San Diego, University of California at Davis, Kaiser Permanente Los Angeles, Loma Linda University, and University of Hawaii) participated in the study. The study was considered exempt from requiring institutional review board approval by the Los Angeles Biomedical Research Institute at Harbor–University of California at Los Angeles. Operative data collected included total cases, major cases, and first-assistant cases. Total cases were defined as a summation of major cases and first-assistant cases. Major cases were defined as those procedures performed primarily by the intern, under faculty supervision, that counted toward the 750 cases required for graduation. First-assistant cases were defined as cases where the intern was primarily assisting the faculty and did not count toward the 750 cases required for graduation. In addition, for major cases, specific types (referred to as defined categories) were obtained including abdomen, endocrine, head and neck, basic laparoscopy, complex laparoscopy, pediatrics, thoracic, soft tissue/breast, trauma, vascular, alimentary, endoscopy, liver, and pancreas surgery. Median values for each data field were calculated for each year. Of note, defined category case data were not obtained for the 2007-2008 academic year owing to difficulties viewing the archived section of the case log website. Program directors were also queried as to the programmatic changes they made to accommodate the duty hours.
Operative data for the interns were collected in an Excel database (Microsoft Excel, Microsoft Corp) for each year and translated into native SAS format using DBMS/Copy (Dataflux Corp). Statistical analyses were performed using SAS version 9.3 (SAS Institute Inc).
Descriptive statistics were evaluated for all variables. Because the operative case volumes were not normally distributed, they are reported as medians with interquartile ranges and were compared using the nonparametric Wilcoxon rank sum test when comparing the 2011-2012 intern class (16-hour work-week era) to the 4 prior academic years (2007-2008, 2008-2009, 2009-2010, and 2010-2011) (pre-16-hour shift limit) combined, and the Kruskal-Wallis test when the 2011-2012 year was compared to each of the prior academic years. The relative proportional decrease in operative volumes is also described. P < .05 was considered statistically significant.
There were 249 categorical interns, including 197 in the pre-16-hour shift restriction period (2007-2010) and 52 in the post-16-hour shift restriction period (2011-2012). For the overall group, the median total cases recorded per intern was 84.0 cases including a median of 75.2 major cases and a median of 18.7 first-assistant cases.
In the 2007-2010 period, the median annual number of total cases per intern was 88.8 compared with 65.9 in the 2011-2012 period (P = .005), representing a 25.8% decrease. The median annual volume of major cases decreased from 80.5 in the 2007-2010 period to 54.9 in 2011-2012 (P < .001), representing a 31.8% decrease. Annual first-assistant case volume decreased from a median of 20.7 cases in the 2007-2010 period to 11.1 in 2011-2012 (P = .008), representing a 46.3% decrease (Table). There were statistically significant decreases in the annual volume of the following defined categories: abdomen, endocrine, head and neck, basic laparoscopy, complex laparoscopy, pediatrics, thoracic, and soft tissue/breast in the 2011-2012 period; whereas, there was no decrease in trauma, vascular, alimentary, endoscopy, liver, and pancreas cases (Table).
Comparing year-to-year median number of cases, a steep decline was noted in the 2011-2012 academic year in total and major cases; a gentler decline was seen in first-assistant cases over the last 5 academic years (Figure). Using the Kruskal-Wallis test for variance, the total case decline generated a P value of .04, the major case decline generated a P value of .002, and the first-assistant case decline generated a P value of .02.
This retrospective review of 10 West Coast general surgery residency programs demonstrated a statistically significant decline in operative volume for categorical interns under the new duty-hour rule that limits interns to a maximum 16-hour shift. Total case volume for the 52 categorical interns studied decreased by 25.8%, major case volume decreased by 31.8%, and first-assistant case volume decreased by 46.3% compared with 249 categorical interns in the pre-16-hour era. Substantial declines were noted across most categories of procedures. Although there were no observed decreases in liver, pancreas, trauma, and vascular cases, these were categories where intern experience was very low at baseline.
The most recent resident duty-hour restrictions were implemented in July 2011. The new rules include a reduction in the maximum shift for PGY 2 residents and greater to 28 hours (from a prior maximum of 30 hours) and a maximum shift of 16 hours for PGY 1 residents.11 The landmark study by Landrigan et al12 in 2004 was a major influence on the new duty-hour regulations. In this study, intensive care unit interns working the traditional 24-hour shift performed nearly 6 times as many serious diagnostic errors as interns who worked shorter duty periods. There was also a 20.8% increase in medication-related errors during traditional 24-hour shifts. Less discussed, but perhaps of even greater consequence, the new duty-hour rules no longer permit PGY 1 residents to take call from home. This was an important change as home call does not count toward the 80-hour work-week restriction; therefore, many surgical residency programs shifted to home call in 2003 to reduce in-hospital work hours. Yet, data to support this new intern home-call restriction is lacking. In fact, in an 11-year study, Kastenberg et al13 recently demonstrated that intern home call did not affect risk-adjusted morbidity or mortality.
The effect of 80-hour per week duty-hour restrictions on surgery resident operative and overall educational experience has been the subject of intense debate. De Virgilio et al1 and Tran et al2 demonstrated that resident operative experience and education remained robust despite the 80-hour work-week restriction. This was achieved by extensively revamping the residency. Many in-house call duties were changed to home call, the residency was expanded, rotations that were of low operative or educational value were eliminated, and high-impact rotations were added. Other studies have reported steep declines in case volume.3,4 Kairys et al4 demonstrated statistically significant decreases in the total major cases and chief level cases.
Operative volume is not the only relevant issue; recent surveys indicated that surgery residents are not uniformly pleased with the new duty hours. In a recent survey of 464 general surgery residents, Lee et al14 reported that 75% were dissatisfied with the 16-hour rule. Senior residents (PGYs 2-5) were more dissatisfied than interns. Most (89%) felt that there was a shift of responsibilities from interns to PGY 2-5 residents, resulting in increased fatigue for the latter. Among PGY 2-5 residents, 94% felt that the 16-hour rule had an adverse impact on intern education as did 75% of interns. In a long-term survey, orthopedic surgery residents reported a decrease in perceived direct clinical experience, number of hours spent performing major procedures, overall satisfaction with education, and sense of clinical preparedness.15 Interestingly, although work hours were significantly reduced from an average of 74.5 hours in 2003 to 66.2 hours in 2009, there was no significant change in the average reported hours of sleep (34.6 hours/week in 2003 vs 33.7 hours/week from 2004-2009).
The decline in operative case volume in our present study is in some respects surprising given that the new duty-hour changes did not mandate a reduction in an overall 80-hour work week for interns. Thus, interns were presumably working the same number of total hours. One potential answer is compliance. Interns may be more compliant with the 80-hour rule when their shifts are already prescheduled and are calculated to not go over 80 hours in a week. A reduced work week may have resulted in less operative experience. A more likely explanation is that many programs, no longer able to allow interns to take home call, have shifted to an intern night-float system to accommodate the 16-hour rule. Prior studies have shown the night-float system is linked to a reduction in operative case volume among senior residents.16
In fact, in the present study, the 10 program directors reported that the predominant solution to the 16-hour rule was an expansion of the night-float system to services previously covered by home call. This resulted in the predictable decrease in time spent on operating services during the day owing to the significantly greater time spent on night float where fewer cases are available for the intern-level experience. Functionally, the service time is actually 14 hours to allow for the requisite 10-hour break between service time (which further reduces contact hours for the intern). It can be anticipated that these deficiencies will prompt the PGY 2 class to attempt to remedy these deficiencies, creating further competition with interns for cases in subsequent years.
Paradoxically, the 16-hour rule may not achieve the intended benefit of reducing intern fatigue. One must consider that the rule permits interns to work up to 6 consecutive 16-hour night shifts, which may considerably alter sleep. Kamine et al17 recently compared the sleepiness of interns who worked a standard 24-hour overnight call every fourth night with interns working a 16-hour night-float system. Sleepiness was measured by the Epworth Sleepiness Scale (range, 0-24; ≤10 normal; >10 indicative of excessive sleepiness). Interns working night float within the 16-hour rule had significantly higher Epworth Sleepiness Scale scores (14.6) than the standard overnight-call interns (9.4) (P = .01). In fact, the average Epworth Sleepiness Scale score with the night float and 16-hour rule was identical to previously published data from before the 80-hour work week.
There are several implications of the reduced operative experience noted in the present study. Categorical interns will enter their PGY 2 even less experienced. This may have a domino effect on subsequent competence. Although the PGY 1 represents 20% of general surgery residency in terms of time, the roughly 80 cases performed by an intern represents only about 8% to 10% of the overall case volume performed during a traditional 5-year surgical residency. Although it is convenient to believe that the decrease in operative volume is unlikely to be catastrophic in terms of overall surgery resident training, it will clearly create a new pool of less-experienced residents at the second-year level. Programs that are already struggling to meet operative case volume and fulfilling the defined categories may be particularly disadvantaged by the PGY 1 case reduction. It remains to be seen whether operative experiences can be expanded for the PGY 2 residents, while also accommodating their learning curve related to managing expanded call requirements. The net impact of these changes raises concerns that the system will need to extend the years of residency training. Given that the US health care system is already struggling to provide funding for graduate medical education and given the rising costs of medical education for students, such a prolongation of surgical residency training is unlikely to be viewed favorably.
Accepted for Publication: April 5, 2013.
Corresponding Author: Christian de Virgilio, MD, Department of Surgery, Harbor–University of California at Los Angeles Medical Center, 1000 W Carson St, PO Box 25, Torrance, CA 90509 (firstname.lastname@example.org).
Published Online: July 10, 2013. doi:10.1001/jamasurg.2013.2677.
Author Contributions:Study concept and design: Schwartz, Galante, Senagore, de Virgilio.
Acquisition of data: Schwartz, Galante, Dolich, Easter, Melcher, Patel, Reeves, Senagore, Takanishi, de Virgilio.
Analysis and interpretation of data: Schwartz, Galante, Kaji, Dolich, Reeves, de Virgilio.
Drafting of the manuscript: Schwartz, Kaji, Salim, Senagore, Takanishi, de Virgilio.
Critical revision of the manuscript for important intellectual content: Schwartz, Galante, Dolich, Easter, Melcher, Patel, Reeves, Senagore, de Virgilio.
Statistical analysis: Kaji.
Administrative, technical, and material support: Dolich, Easter, Patel, Reeves, Salim, Takanishi.
Study supervision: Galante, Reeves, Senagore, de Virgilio.
Conflict of Interest Disclosures: None reported.
Previous Presentation: This study was presented at the 84th Annual Meeting of the Pacific Coast Surgical Association; February 17, 2013; Kauai, Hawaii, and is published after peer review and revision.