Cost-Effectiveness of Linaclotide Compared to Osmotic Laxatives in the Treatment of Irritable Bowel Syndrome with Constipation in China.

Introduction: Linaclotide, a selective agonist of guanylate cyclase C, was highly recommended for the treatment of irritable bowel syndrome with constipation (IBS-C). However, the cost-effectiveness of linaclotide in Chinese is not known, and this study aimed to assess the cost-effectiveness of linaclotide for patients with IBS-C.

Methods: An economic evaluation was conducted with a Markov model from a societal perspective. The Markov model was structured to simulate the discontinuation and continuation of medication in IBS-C patients in clinical practice, as well as the revisit and non-visit of non-responding patients. The cycle of the model was 4 weeks, and the time horizon was 1 year. The efficacy data in the model was from the risk ratios obtained by the meta-analysis and the calculation of the response rate of the three medications. The utility, discontinuation rate of the medication, and revisit rate data were from published literature, while the cost data were obtained from experts' opinions and published literature. A series of sensitivity analyses was performed on parameters potentially having impact on the model outputs.

Results: The QALYs (quality-adjusted life years) gained for 1-year treatment with linaclotide, polyethylene glycol, and lactulose were 0.821, 0.795, and 0.781, respectively. The corresponding total costs were CNY 7,721 (USD 1,120), CNY 8,797 (USD 1,276) and CNY 9,481 (USD 1,375). In both comparisons, linaclotide was dominant. Compared with polyethylene glycol and lactulose, the likelihood of linaclotide being cost-effective was 100% for both, using 1 times per capita GDP per QALY as willingness-to-pay threshold.

Conclusions: IBS-C seriously affects the quality of life of patients with IBS-C, and linaclotide can improve symptoms and quality of life at less cost.