Health Care Use and Costs of Children, Adolescents, and Young Adults With Somatic Symptom and Related Disorders

This cohort study uses data from linked health and administrative databases in Ontario, Canada, to investigate health care use and costs among children, adolescents, and young adults diagnosed with somatic symptom and related disorders.


Introduction
Somatic symptom and related disorders (SSRDs) are highly prevalent and account for a large proportion of health system visits. [1][2][3][4][5] Presentation of these psychiatric disorders can be varied, but the core features are physical symptoms inconsistent with history, physical examination, or laboratory or imaging investigations. 2,4,6,7 Types of SSRDs include somatic symptom disorder, conversion disorder (also called functional neurological symptom disorder), illness anxiety disorder, and psychological factors affecting medical conditions. 8 In these disorders, psychological or emotional distress is experienced through physical symptoms, known as somatic symptoms.
Associated terms include functional disorders and, historically, medically unexplained symptoms. 4,9 There is overlap in the diagnostic classification of SSRDs with other conditions, such as fibromyalgia, irritable bowel syndrome, and chronic fatigue syndrome. [10][11][12] SSRDs are associated with considerable impairment in functioning, including school absenteeism, social isolation, reduced quality of life, unnecessary and sometimes harmful diagnostic testing, and delays in appropriate treatment and intervention for what is actually a primary mental health disorder. 1,2,13 Delays in diagnosis and treatment often lead to frustration and worry in patients and families who may feel dismissed. 1 Similarly, health care professionals experience distress in failing to improve their patients' functioning. 13 An SSRD contributes to substantial personal, health system, and societal costs. 9,14-16 Some work has been done in adults to better characterize health system use and costs in these populations, but little has been done in children, adolescents, and young adults. 9,14,17,18 Although most patients with somatic symptoms are seen in primary care settings, 13,17 a proportion of individuals may be so distressed or impaired by their symptoms that they seek care in an emergency department (ED) or are hospitalized (becoming inpatients). In these latter settings, patients may present with a more severe form of the disorder, with high intensity and often unmet health care needs. 1,2,19 Identification or diagnosis of the disorder, regardless of setting, represents an opportunity for intervention, but acceptance of diagnosis and navigation of treatment pathways are often not easy. 2 Given the barriers to appropriate care that these patients face, characterizing the patterns of health care use, including the setting in which patients receive their diagnosis and the care received after somatic symptoms have been identified along with associated costs, will shed light on the magnitude of the issue and opportunities for intervention. Our objectives were to describe the sociodemographic and clinical characteristics of children, adolescents, and young adults with an SSRD in Ontario, Canada's largest province with a population of almost 14 million, and to describe the patterns of health care use and costs in the population in the year leading up to and the year after diagnosis.

Study Design
Databases are linked through a uniquely encoded health identification number derived from the health card number of every resident in Ontario with provincial health insurance. Research ethics board approval for this study was received from The Hospital for Sick Children. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.

Data Sources
The study cohort was constructed using diagnostic codes from provincial portions of hospital

Study Population
All children, adolescents, and young adults aged 4 to 24 years living in Ontario between April 1, 2008, and March 31, 2015, were included. A cutoff age of 24 years was used, as this is the age cutoff used to define youth by the United Nations. 20 This age group was further stratified as children (4-12 years), adolescents (13-17 years), and young adults (18-24 years). The study cohort comprised any individual who was seen as an outpatient and had a physician billing code for psychosomatic disturbances (Ontario Health Insurance Plan diagnostic code 306) or any individual who was discharged from a hospital or ED with a discharge diagnosis that included any of the following: somatization disorder, conversion disorder, factitious disorder, irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, or other related disorders using the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision-Canada (ICD-10-CA) diagnostic codes (eTable 2 in the Supplement). No validated definition of an SSRD using health and administrative data from ICD-10-CA codes exists, nor is there consensus on clinical diagnoses. However, these health care professional-assigned diagnoses from clinical encounters were chosen because they are the most commonly used for research in SSRDs. [21][22][23] The first date on which individuals had their SSRD diagnosis in any of the outpatient or acute care databases was considered the index date. A 2-year lookback was used to ascertain that the visit was the first time somatic symptoms were documented and to identify the clinician who provided the majority of primary care. We categorized continuity of primary care in the 2 years leading up to the index SSRD visit as low, moderate, and high with cutoffs of less than 50%, 50% to 79.9%, and 80% or more of all primary care visits to their assigned primary care professional.
Health care costs were based on unit costs of services provided to patients during an episode of care, paid by the Ontario Health Insurance Plan to eligible health care professionals. Acute hospitalizations and ED visit costs were calculated using case-mix methodology, in which the cost of a patient encounter is based on the intensity of resources used during the episode of care. Psychiatric hospitalization costs were determined using measures of resource intensity, days of stay, and case-mix index. Additional information on case-mix costing methodology in Ontario is available and published elsewhere. 25

Health Care Costs
The Ambulatory care accounted for a relatively small proportion of total costs (Figure). Two-year mean (SD) per-patient expenditure was $9562 ($24 959) and $5249 ($32 928) for patients diagnosed in ED and outpatient settings, respectively. Costs before and after diagnosis overall and by sector are shown in eTable 4 in the Supplement.

Discussion
In this population-based cohort study, we identified and described a population of children, adolescents, and young adults with health system records of an SSRD who have substantial health system use and costs. Per capita costs of hospitalized young people with this disorder were 16 to 20 times the published costs of their peers in Ontario, which range from $1494 to $1843 among young people aged 5 to 24 years. 26 We report frequent health care use in the year leading up to a health record diagnosis that continues in the year after diagnosis, and our results suggest that follow-up care by physicians and specialists for mental health care was poor. The frequent health care use before index diagnosis suggests that SSRDs may go under-recognized for a prolonged period. The low rate of physician follow-up for mental health care and high rates of ongoing non-mental health system use suggest that a diagnosis in and of itself is not sufficient to lead to a shift in the treatment trajectory toward what might potentially be more effective care for the presenting signs and symptoms. Importantly, despite having a primary mental health condition, many patients did not receive timely mental health support from a physician, particularly hospitalized school-aged children.
Initiatives to recognize SSRDs and to ensure supports are put in place early are warranted.
Somatic symptoms are a common reason for medical visits in young children. 1,2,4,5 In adults, prevalence estimates for those with any SSRD are upwards of one-third of patients in primary care, and approximately 8% of patients present with multiple concurrent somatic symptoms. 14,17,23 Studies of adults with an SSRD have reported a mean of 12.8 outpatient physician or nurse practitioner visits per year with nonspecific symptoms, 23 and there is high comorbidity with other mental illnesses, including depression, anxiety, and substance use disorder. [27][28][29] Our cohort of children, adolescents, and young adults similarly had high numbers of outpatient visits, inpatient hospitalizations, and emergency visits for comorbid mental illness. A large proportion of revisits in the year after diagnosis in our cohort were for mental illness, yet outpatient physician visits for mental health concerns remained low. Early mental health consultation during inpatient hospitalization has been shown to reduce the length of hospital stay in children with comorbid mental health diagnoses, including those with SSRDs. 30 A number of feasible and some costeffective primary care and transitional interventions have been identified to potentially reduce psychiatric readmission or improve quality of life and could be considered in the population. [31][32][33][34] Health care costs of children, adolescents, and young adults in Canada with SSRDs have not, to our knowledge, been previously reported. Our data suggest that per capita costs for these patients Figure Identifying those who frequently use the health system has been recognized as an important step to improve health system sustainability, quality of care, and patient outcomes. 35,42 This identification facilitates improved patient management through better understanding of the clinical needs of the population of patients who frequently use health services and allows services to be targeted appropriately. 35 Care for those with an SSRD has been described as fragmented, uncoordinated, and difficult to navigate because of the multiple health care practitioners involved. 1,2,43,44 Thus, this is a patient population in which high-intensity, coordinated, and timely integrated care may be of benefit. Integrated models of care for children, adolescents, and young adults with an SSRD have shown some promise in improving outcomes through a coordinated approach that de-emphasizes medicalizing symptoms, and instead supports the mind-body connection in outpatient settings. 2,[45][46][47] Because such care models can be costly, they need to be targeted to those who would benefit most or to those who incur the greatest cost to maximize the potential for cost offset. Importantly, in pediatric populations, early-life health care use for functional disorders is associated with future health care use. Other researchers have also shown that SSRDs in adolescence are predictive of severe mental illness in adults, as measured by hospital-based mental health care, even when controlling for confounders. 48 Although two-thirds of our cohort were emerging adults, a sizable proportion were school-aged children and adolescents. Interventions in early childhood have the potential to both reduce the distress of this patient population and reduce costs associated with frequent health care use in this patient population.

Limitations
There are important limitations to this study. We ascertained our cohort from individuals who had a health record rather than a clinical diagnosis of an SSRD and, therefore, did not capture individuals who had functional symptoms but were not recorded in the inpatient and ED discharge records or in physician billing records. Therefore, we likely underestimated the overall health system use and costs of SSRDs. We do not have health and administrative data on social workers and psychologists who may provide some mental health treatment for individuals with functional disorders; therefore, we cannot fully describe the mental health services delivered to these children before and after diagnosis. Databases do not capture private drug and home care (eg, occupational therapy and physiotherapy) coverage and care provided in community health centers (<1% of the population), 49 which do not bill through fee-for-service. Importantly, we do not capture indirect health costs, including caregiver costs, particularly from lost parental employment time. There is a lack of a unified and validated definition of SSRD using administrative data and for other research purposes.
Diagnoses were from physicians and noted in health records rather than obtained through any specific SSRD measurement tool for diagnosis, as no such validated tool currently exists or is available in administrative data.