Cost-effectiveness analysis of adjunct VSL#3 therapy versus standard medical therapy in pediatric ulcerative colitis

Inflammatory bowel diseases (IBDs) are costly chronic gastrointestinal diseases, with pediatric IBD representing increased costs per patient compared to adult disease. Health care expenditures for ulcerative colitis (UC) are >$2 billion annually. It is not clear whether the addition of VSL#3 to standard medical therapy in UC induction and maintenance of remission is a cost-effective strategy.

We performed a systematic review of the literature and created a Markov model simulating a cohort of 10-year-old patients with severe UC, studying them until 100 years of age or death. We compared 2 strategies: standard medical therapy versus medical therapy + VSL#3. For both strategies, we assumed that patients progressed through escalating therapies--mesalamine, azathioprine, and infliximab--before receiving a colectomy + ileal pouch anal anastamosis (IPAA) if the 3 medical therapy options were exhausted. The primary outcome measure was the incremental cost-effectiveness ratio (ICER), defined as the difference of costs between strategies for each quality-adjusted life-year (QALY) gained. One-way sensitivity analyses were performed on variables to determine the key variables affecting cost-effectiveness.

Standard medical care accrued a lifetime cost of $203,317 per patient, compared to $212,582 per patient for medical therapy + VSL#3. Lifetime QALYs gained was comparable for standard medical therapy and medical therapy + VSL#3 at 24.93 versus 25.05, respectively. Using the definition of ICER <50,000/QALY as a cost-effective intervention, medical therapy + VSL#3 produced an ICER of $79,910 per QALY gained, making this strategy cost-ineffective. Sensitivity analyses showed that 4 key parameters could affect the cost-effectiveness of the 2 strategies: cost of colectomy + IPAA, maintenance cost after surgery, probability of developing pouchitis after surgery, and the quality of life after a colectomy + IPAA. High surgical and postsurgical costs, a high probability of developing pouchitis, and a low quality of life after a colectomy + IPAA could make adjunct VSL#3 use a cost-effective strategy.

Given present data, adjunct VSL#3 use for pediatric UC induction and maintenance of remission is not cost-effective, although several key parameters could make this strategy cost-effective. The quality of life after an IPAA is the single most important variable predicting whether this procedure benefits patients over escalating standard medical therapy.