Objective: Few studies have assessed the influence of inflammatory bowel disease (IBD) on work loss or estimated the costs related to work loss. Our analysis reports the employment effects related to IBD as based on the 1998 sample of the Canadian National Population Health Survey (NPHS).
Methods: Our predictive analysis adapts the theory of labor supply to a health context. Respondents between the ages of 20 and 64 who reported that they had been diagnosed by a health professional to have "a bowel disorder such as Crohn's disease or colitis" were distinguished from the other respondents. A logistic regression model was used to estimate the OR for labor force nonparticipation and variables predictive of it in the case of IBD. For those people in the labor force, the Cox proportional hazard model was used to determine whether having IBD and similar bowel disorders had an effect on the number of months of continuous employment.
Results: Of the IBD patients 28.9% reported labor force nonparticipation, which was a greater proportion than the non-IBD respondents (18.5% nonparticipation). The OR was 1.20 (95% CI = 1.19-1.21) for nonparticipation of IBD patients versus non-IBD patients controlling for potentially confounding factors. We estimated the excess nonparticipation attributable to IBD and similar bowel disorders in Canada to be 2.9%. Based on this, the indirect cost of nonparticipation attributable to IBD in 1998 was >$104.2 million Canadian dollars. According to the second regression using the Cox proportional hazard model, IBD and similar bowel disorders were not significantly related to the number of months worked until a break in employment was reported. Thus, there was no excess work loss among those who were employed that was associated with IBD.
Conclusions: By using directly observed data in our analysis, this method of estimation can predict the overall burden of IBD and similar bowel disorders, controlling for the effect of other potentially influential characteristics.