A case-control comparison of direct healthcare-provider medical costs of chronic idiopathic constipation and irritable bowel syndrome with constipation in a community-based cohort

Abstract

Objective: Patients with constipation account for 3.1 million US physician visits a year, but care costs for patients with irritable bowel syndrome with constipation (IBS-C) or chronic idiopathic constipation (CIC) compared to the general public have received little study. The study aim was to describe healthcare utilization and compare medical costs for patients with IBS-C or CIC vs matched controls from a community-based sample.

Methods: A nested case-control sample (IBS-C and CIC cases) and matched controls (1:2) for each case group were selected from Olmsted County, MN, individuals responding to a community-based survey of gastrointestinal symptoms (2008) who received healthcare from a participating Rochester Epidemiology Project (REP) provider. Using REP healthcare utilization data, unadjusted and adjusted standardized costs were compared for the 2- and 10-year periods prior to the survey for 115 IBS-C patients and 230 controls and 365 CIC patients and 730 controls. Two time periods were chosen as these conditions are episodic, but long-term.

Results: Outpatient costs for IBS-C ($6,800) and CIC ($6,284) patients over a 2-year period prior to the survey were significantly higher than controls ($4,242 and $5,254, respectively) after adjusting for co-morbidities, age, and sex. IBS-C outpatient costs ($25,448) and emergency room costs ($6,892) were significantly higher than controls ($21,024 and $3,962, respectively) for the 10-year period prior. Unadjusted data analyses of cases compared to controls demonstrated significantly higher imaging costs for IBS-C cases and procedure costs for CIC cases over the 10-year period.

Limitations: Data were collected from a random community sample primarily receiving care from a limited number of providers in that area.

Conclusions: Patients with IBS-C and CIC had significantly higher outpatient costs for the 2-year period compared with controls. IBS-C patients also had higher ER costs than the general population.

Keywords:

• Costs
• Irritable bowel syndrome with constipation
• chronic idiopathic constipation
• economic burden
• healthcare resource utilization

Transparency

Declaration of funding

Study data were obtained from the Rochester Epidemiology Project, which is supported by the National Institute on Aging of the National Institutes of Health (grant R01 AG034676). Ironwood Pharmaceuticals funded the data abstraction and analysis of costs.

Declaration of financial/other relationships

LH has stock ownership in Hormel, Corp; YS serves as a consultant/advisor for Commonwealth Labs, and participated in advisory boards for Synergy and Salix; WS was an employee with stock ownership of Ironwood Pharmaceuticals, Inc. JME peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgments

The investigators would like to thank Nilay Shah, PhD, Health Care Policy and Research, Mayo Clinic, Rochester, MN, for his input and guidance on the statistical analysis. The investigators would also like to thank G. Richard Locke, III, MD, Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, for his input and guidance on the data and interpretation of results.