Incremental Healthcare Costs Associated with Chronic Constipation: A Retrospective Claims Analysis

Abstract

Purpose: The estimated prevalence of chronic constipation (CC) is approximately 12-19% in the US; however, healthcare costs associated with this condition are not well understood. The objective of this study is to evaluate incremental costs associated with CC in patients in a managed care population. Methods: Patients were identified from the HealthCore Integrated Research Database, which consists of approximately 45 million members from 14 geographically-dispersed health plans. Inclusion criteria for CC patients were: (1) age ≥18 years as of January 1, 2010; (2) continuously eligible in 2010; (3) >2 medical claims for constipation (ICD-9-CM code 564.0x) occurring ≥90 days apart or ≥1 medical claim for constipation plus ≥1 constipation-related pharmacy claim occurring ≥90 days apart. Patients with irritable bowel syndrome (ICD-9-CM code 564.1x) or diagnoses or prescriptions suggesting chronic diarrhea or drug induced constipation were excluded. A control group without irritable bowel syndrome, constipation, abdominal pain, or bloating was randomly selected using 1:1 matching on age, gender, health plan region, and plan type. All-cause medical services included inpatient visits, emergency room (ER) visits, physician office visits, and other outpatient services for any condition. Total healthcare costs included costs from medical services and pharmacy costs. Generalized linear models with bootstrapping were used to evaluate the incremental costs attributable to CC, after adjusting for a series of confounders including demographics, Elixhauser comorbidity index (ECI) score, and 15 general and gastrointestinal-related comorbidities not included in the ECI score (e.g., chronic pain, hyperlipidemia, gastro esophageal reflux disorder, hemorrhoids). Results: A total of 14,854 patients (n=7,427 for CC and matched controls, respectively) met the inclusion criteria. The mean age of CC patients and matched controls was 58.7 years; 75.4% were female. CC patients had higher unadjusted all-cause healthcare costs versus controls ($11,991 vs. $3,278, p<0.01). Nearly half of this difference (44.1%) was due to physician office visits and other outpatient services/diagnostics (8.9% and 35.2%, respectively). The remaining difference was attributable to hospitalizations (37.8%), prescriptions (14.3%), and ER visits (3.8%). After adjusting for demographics and comorbidities, the adjusted incremental all-cause costs for CC patients were $3,508 (in 2010 US dollars), of which 81.0% were for medical services (see Table).Table: Adjusteda mean all-cause costs for CC patients and controls in 2010Conclusion: CC imposes a significant economic burden even after controlling for demographic and clinical comorbidities. Incremental costs were mainly driven by medical services as opposed to prescription use. Disclosure: Qian Cai, Abhishek Kavati, Hiangkiat Tan, and Judith Stephenson: employees of Healthcore, Inc., which is a consultancy whose activities related to the project are funded by Forest Laboratories, Inc., and Ironwood Pharmaceuticals; Robyn Carson and Jessica Buono: employees of Forest Laboratories, Inc. and own stock and/or stock options in Forest Laboratories, Inc.; Phil Sarocco and William Spalding: employees of Ironwood Pharmaceuticals, Inc. and own stock and/or stock options in Ironwood Pharmaceuticals. This research was supported by an industry grant from Forest Laboratories, Inc., and Ironwood Pharmaceuticals, Inc., were involved in the study design; collection, analysis and data interpretation; and decision to submit these data for presentation. Study was sponsored by Forest Laboratories, Inc., and Ironwood Pharmaceuticals, Inc.