Economic Burden of Irritable Bowel Syndrome (IBS) With Diarrhea (IBS-D): Retrospective Analyses of a US Commercially Insured Population: 2222

Introduction: IBS-D affects ˜5% of the US adult population but the economic burden is not well understood. This study aimed to estimate incremental costs of IBS-D in a US commercially insured population. Methods: Patients (pts) aged ≥18 years with continuous medical and pharmacy benefit eligibility between 1/1/2013 and 12/31/2013 were identified from the Truven Health MarketScan Database. IBS-D pts had ≥1 medical claim for IBS (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] code 564.1x) and either ≥2 claims for diarrhea (ICD-9-CM code 787.91, 564.5x) or ≥1 claim for diarrhea plus ≥1 claim for abdominal pain (ICD-9-CM code 789.0x) or ≥1 claim for diarrhea plus ≥1 pharmacy claim for a symptom-related (i.e. IBS, diarrhea, or abdominal pain) prescription during the study period. Controls without IBS, diarrhea, or abdominal pain were randomly selected using 1:1 matching on age, gender, geographic location, and health plan type. Pts with diagnoses or prescriptions suggesting mixed IBS, IBS with constipation, chronic constipation, or drug-induced diarrhea were excluded. All-cause medical services included hospitalizations, emergency room (ER) visits, physician office visits, and other outpatient (OP) services (e.g. diagnostic/laboratory tests, OP procedures) for any condition. Total healthcare costs consisted of costs from medical and pharmacy services. Generalized linear models assessed incremental costs attributable to IBS-D, adjusting for demographics, Elixhauser comorbidity index (ECI) score, and 14 general and 11 gastrointestinal-related comorbidities not included in the ECI score. Results: Of 39,306 pts (n=19,653 IBS-D) identified, mean (± SD) age was 47 ± 17 years; 76.5% were female. IBS-D pts had significantly higher unadjusted all-cause healthcare costs compared to controls ($13,038 vs. $4,109; p < 0.01). Most of this difference (74.7%) was due to hospitalizations, ER visits, and other OP services (12.5%, 10.5%, and 51.7%, respectively). The remaining difference was due to prescriptions (17.1%) and physician office visits (8.2%). After adjusting for demographics and comorbidities, incremental total all-cause healthcare costs associated with IBS-D were $2,696 (in 2013 US $), of which 79.2% was for medical services (Table).Table 1: Adjusteda Mean All-Cause Costs for IBS-D Pts and Controls in 2013Conclusion: IBS-D is associated with a substantial economic burden even after controlling for comorbidities. Most incremental costs are attributable to medical services. (Support: Actavis, Inc.)