OBJECTIVES : To assess the long-term cost-effectiveness of tight control (TC) for Crohn’s disease, using biomarkers (fecal calprotectin and C-reactive protein), compared to clinical management (CM) using data from the 48-week CALM trial under Brazilian public healthcare system (SUS) perspective.

METHODS : Based on the CALM trial, CDAI was used to map patients into four health states (remission: CDAI<150, moderate: CDAI≥150 to <300, severe: CDAI≥300 to <450, very severe: CDAI≥450) weekly and projected to 5 years; likelihood of hospitalization was estimated by a probit regression. Number of adalimumab injections was estimated from CALM trial. Adalimumab cost was based on public purchase. Other medical costs associated with health states were derived from published Brazilian research. Remission rate, CD-related hospitalizations, adalimumab injections, other direct medical costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) were calculated at 2 and 5 years. Probabilistic sensitivity analyses (PSA) were conducted to include work productivity measures using Brazilian minimum hourly wage.

RESULTS : Over 2 years, TC was associated with a higher remission rate (65.3% vs 50.7%), fewer CD-related hospitalizations (0.275 vs 0.720/person yr) and more ADA injections (mean 61.34 vs 46.17) than CM. TC vs CM had 0,085 higher QALYs (95% confidence interval [CI]: 0,03 to 0,15) and R$3.724 higher total medical costs (95%CI: R$-3.349 to R$5.797). The ICER was R$44.033 per QALY (95%CI: R$-35.918 to R$173.521) in the base case, decreasing to R$33.975 when considering work productivity gained. PSA simulations indicated 88.3% of the time an ICER was below a cost-per-QALY threshold of R$91.221 (3x Brazilian per-capita GDP). The results for 5-yr timeframe were similar, with an ICER of R$40.042 in the base case and R$30.407 considering work productivity costs.

CONCLUSIONS : Cost-effectiveness of TC improved over time when extrapolating outcomes from the CALM trial. Incorporating costs related to work productivity further strengthened the economic value of TC.