Cost utility of vitamin D supplementation in adults with mild to moderate asthma

Abstract

Objective: Uncontrolled asthma significantly impairs health-related quality of life and work productivity. Some add-on therapies, such as vitamin D supplements, safely reduce the rate of asthma exacerbation. The purpose of this study was to assess the cost-utility of vitamin D supplementation in adults with mild to moderate persistent asthma in Colombia.

Methods: A Markov model was created to estimate the cost and quality-adjusted life-years (QALYs) of patients with severe asthma in Colombia. Total costs and QALYs of two therapy strategies, vitamin D supplementation plus ICS versus ICS alone, were calculated over a one-year time horizon. Deterministic and probability sensitivity analyses were conducted, and cost-effectiveness was evaluated at a willingness-to-pay value of $5,180 per QALY gained.

Results: The base-case analysis showed that compared with no supplementation, vitamin D supplementation was associated with higher costs and higher QALYs. The expected annual cost per patient with vitamin D supplementation was US$1338 and without this supplementation it was US$1095. The QALYs per person estimated with vitamin D supplementation was 0.80, and without this supplementation it was 0.63. The estimated incremental cost-effectiveness ratio (ICER) was US$1583 per QALY.

Conclusions: Add-on vitamin D supplement was cost-effective when added to the usual care in patients with mild to moderate persistent asthma. Our study provides evidence that should be used by decision-makers to improve clinical practice guidelines.

Keywords: Markov model; Vitamin D; cost-effectiveness analysis; decision analysis; uncontrolled asthma.