Disease activity, behavioral dysfunction, and health-related quality of life in adolescents with inflammatory bowel disease.

Crohn’s disease and ulcerative colitis (collectively known as inflammatory bowel disease; IBD) are chronic conditions characterized by uncontrolled intestinal inflammation and periods of disease activity and remission.1 An estimated 20-25% of all IBD cases have an onset in childhood or adolescence,2-3 with a median age at diagnosis of 15 years and an incidence of 71 per 100,000.4 Children and adolescents with IBD must often deal with unpredictable, unpleasant, and potentially embarrassing gastrointestinal symptoms (e.g., abdominal pain, diarrhea, rectal bleeding) in addition to treatment-related side-effects and burden.1 Though treatment of IBD varies by individual case presentation, regimens are often complex and may consist of multiple medication doses per day, dietary modifications, and, in some cases, surgical intervention.5 Though the goal of medical treatment is to minimize symptom activity and disease-related complications, it is clear that IBD and its treatment impact many areas of patient functioning beyond physical health. As such, there is an increasing need to conceptualize patient health more broadly by incorporating assessments of patient emotional and social well-being into treatment decision making and estimates of health outcome. This is especially true given increased focus on improving long-term patient outcomes.6 Health-related quality of life (HRQOL) measures a patient’s perception of their health status and the impact of their illness on their physical, social, and emotional functioning.3 Though HRQOL research in the adult IBD literature has been examined extensively,7-8 there is considerably less inferential research on HRQOL in pediatric IBD. In particular, there is scant evidence regarding predictors of HRQOL in pediatric IBD. Thus, little is known about patient factors that are associated with better or worse quality of life outcome in children and adolescents with IBD. Among the extant research, disease activity has emerged as a consistent predictor of HRQOL in pediatric IBD. Compared to individuals whose symptoms are quiescent or in remission, children/adolescents with greater disease activity report lower levels of HRQOL.3, 6 Though this relationship makes intuitive sense as lowered HRQOL may be due in part to the functional impairment of increased gastrointestinal symptoms and perhaps side-effects of more aggressive treatment to control symptoms, this is a unidimensional conceptualization of HRQOL, which is a multidimensional construct. Disease severity accounts for a relatively small proportion of variance in HRQOL in this population3, suggesting that other factors may contribute to HRQOL. Moreover, research examining the mechanisms through which disease activity impacts HRQOL is greatly needed as this is a poorly understood yet important area of research and clinical care. Indeed, because,other factors that either improve or worsen HRQOL have not yet been identified,9 our ability to design interventions to improve HRQOL and maximize health outcome is limited. Thus, it is imperative that research articulates the relationship between disease activity and HRQOL by examining a broader range of factors related to patient’s quality of life. Because social and emotional factors are significant aspects of overall HRQOL, behavioral dysfunction may explain a portion of the variance in HRQOL. Behavioral dysfunction refers to both internalizing symptoms (e.g., anxiety, depression) and externalizing symptoms (e.g., aggression, disruptive behavior). Several studies have examined rates of behavioral dysfunction in children with IBD and healthy controls. In general, children with IBD are at greater risk of having problems in emotional and behavioral functioning (Mackner et al., 2006) and are rated by their parents as displaying greater levels of internalizing symptoms (e.g., anxiety, depression) than healthy controls.10-11 Although the relationship between behavioral dysfunction and HRQOL has been documented in other chronic illness groups, 12-13 this has not been examined in the pediatric IBD population. Currently, many gaps exist in the research literature with regard to HRQOL in adolescents with IBD. Disease severity only explains a small portion of the variance in HRQOL and little is known regarding other factors that may impact HRQOL or the mechanisms through which disease activity impacts HRQOL. Based on research in other pediatric populations, one potential factor that may increase our understanding of HRQOL outcome in IBD is behavioral dysfunction. To this end, the current study was designed to examine the relationship among behavioral dysfunction and disease activity with HRQOL in a sample of adolescents with IBD. Greater behavioral dysfunction and greater disease severity were hypothesized to predict poorer HRQOL. Furthermore, behavioral dysfunction was expected to mediate the relationship between disease activity and HRQOL.