Contrasting Clinician and Insurer Perspectives to Managing Irritable Bowel Syndrome: Multilevel Modeling Analysis

Insurance coverage is an important determinant of treatment choice in irritable bowel syndrome (IBS), often taking precedence over desired mechanisms of action or patient goals/values. We aimed to determine whether routine and algorithmic coverage restrictions are cost-effective from a commercial insurer perspective.

A multilevel microsimulation tracking costs and outcomes among 10 million hypothetical moderate-to-severe patients with IBS was developed to model all possible algorithms including common global IBS treatments (neuromodulators; low fermentable oligo-, di-, and mono-saccharides, and polyols; and cognitive behavioral therapy) and prescription drugs treating diarrhea-predominant IBS (IBS-D) or constipation-predominant IBS (IBS-C) over 1 year.

Routinely using global IBS treatments (central neuromodulator; low fermentable oligo-, di-, and mono-saccharides, and polyols; and cognitive behavioral therapy) before US Food and Drug Administration-approved drug therapies resulted in per-patient cost savings of $9,034.59 for IBS-D and $2,972.83 for IBS-C over 1 year to insurers, compared with patients starting with on-label drug therapy. Health outcomes were similar, regardless of treatment sequence. Costs varied less than $200 per year, regardless of the global IBS treatment order. The most cost-saving and cost-effective IBS-D algorithm was rifaximin, then eluxadoline, followed by alosetron. The most cost-saving and cost-effective IBS-C algorithm was linaclotide, followed by either plecanatide or lubiprostone. In no scenario were prescription drugs routinely more cost-effective than global IBS treatments, despite a stronger level of evidence with prescription drugs. These findings were driven by higher prescription drug prices as compared to lower costs with global IBS treatments.

From an insurer perspective, routine and algorithmic prescription drug coverage restrictions requiring failure of low-cost behavioral, dietary, and off-label treatments appear cost-effective. Efforts to address insurance coverage and drug pricing are needed so that healthcare providers can optimally care for patients with this common, heterogenous disorder.