Electronic Theses and Dissertations

Date of Award


Document Type


Degree Name

M.S. in Pharmaceutical Science


Pharmacy Administration

First Advisor

Donna West-Strum

Second Advisor

Rahul Khanna

Third Advisor

Yi Yang

Relational Format



Objective: to determine the period prevalence of IBS and comorbid depression among individuals with Irritable Bowel Syndrome (IBS) in multi-state Medicaid population, and to assess the impact of comorbid depression on healthcare utilization and costs among individuals with IBS enrolled in fee-for-service Medicaid program. Methods: a retrospective cohort study was conducted using 2006-2008 Medicaid analytic extract files for 39 states. Beneficiaries with IBS were identified based on any medical claims for the disease. Beneficiaries with one or more medical claims for depression during the study period were considered to have had comorbid depression. For each beneficiary, the first claim for IBS in 2007 was considered as the index date. 12-month post index date all-cause and IBS-related healthcare utilization and costs were computed for each of the four medical service components “inpatient, outpatient, emergency room, and prescription drug. Generalized linear models were used to assess the impact of comorbid depression on healthcare utilization and costs. Results: the period prevalence of IBS in the population was 4.4 per 1,000 Medicaid beneficiaries. The period prevalence of comorbid depression among beneficiaries with IBS was 26.88%. Beneficiaries with IBS and depression had significantly greater all-cause and IBS-related inpatient, IBS-related outpatient, all-cause emergency room, all-cause and IBS-related prescription drug utilization, and IBS-related outpatient, all-cause and IBS-related emergency room, and all-cause and IBS-related prescription drug costs as compared to those without depression. Conclusion: given the impact on healthcare use and costs, there is a need for better screening and management of depression in this population.



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