Annual Direct and Indirect Cost of Illness in Employees with Irritable Bowel Syndrome Plus Constipation

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Purpose: To assess the annual direct and indirect cost of illness for irritable bowel syndrome plus constipation (IBS+C) among U.S.-based employees. Methods: A retrospective analysis was conducted using the Human Capital Management Services Research database, which contains employee data from 2001–2005 sourced from multiple U.S.-based employers. Data fields included medical, pharmacy, payroll, work absence (where available), and demographics. The IBS+C cohort consisted of employees identified with ICD-9 Codes 564.0 (Constipation), 564.00 (Unspecified), 564.01 (Slow Transit), or 564.09 (Other) co-occuring with 564.1x (IBS) in the same year. Employees with no claims for these codes comprised the Control cohort. The annual measurement period for each IBS+C subject began 3 months prior to the first date of service associated with IBS or C. For controls, the index date was the average index date of subjects with IBS+C. Two-part regression modeling was used to determine the annual cost differences between IBS+C and Control cohorts while controlling for age, job tenure, gender, salary, region, and Charlson Comorbidity Index score. Direct (inpatient and outpatient visits, prescription drug) and indirect (sick leave, and short-term disability [STD]) costs were analyzed. Results: Data were available for 296,154 employees. IBS+C employees compared to Controls were more frequently (P < 0.05) female (80.2% vs. 42.0%), not married (51.8% vs. 43.8%), and employed full time (95.5% vs. 88.6%). All annual cost outcomes comparisons (Table) were statistically greater in the IBS+C cohort (P < 0.05). IBS+C was associated with an annual mean incremental direct cost versus controls totaling $3,590; medical costs accounted for 80% of the direct cost difference and prescription drug costs 20%. IBS+C was also associated with $702 incremental indirect costs. IBS+C contributed 1.89 incremental sick leave days (P < 0.05) but differences in STD days were not significant.TableConclusion: IBS+C is associated with significant cost and absenteeism; in this study, the majority of total incremental costs were direct medical.