Adherence to the iDSI reference case among published cost-per-DALY averted studies

BACKGROUND: The iDSI reference case, originally published in 2014, aims to improve the quality and comparability of cost-effectiveness analyses (CEA). This study assesses whether the development of the guideline is associated with an improvement in methodological and reporting practices for CEAs using disability-adjusted life-years (DALYs). METHODS: We analyzed the Tufts Medical Center Global Health CEA Registry to identify cost-per-DALY averted studies published from 2011 to 2017. Among each of 11 principles in the iDSI reference case, we translated all methodological specifications and reporting standards into a series of binary questions (satisfied or not satisfied) and awarded articles one point for each item satisfied. We then calculated methodological and reporting adherence scores separately as a percentage of total possible points, measured as normalized adherence score (0% = no adherence; 100% = full adherence). Using the year 2014 as the dissemination period, we conducted a pre-post analysis. We also conducted sensitivity analyses using: 1) optional criteria in scoring, 2) alternate dissemination period (2014–2015), and 3) alternative comparator classification. RESULTS: Articles averaged 60% adherence to methodological specifications and 74% adherence to reporting standards. While methodological adherence scores did not significantly improve (59% pre-2014 vs. 60% post-2014, p = 0.53), reporting adherence scores increased slightly over time (72% pre-2014 vs. 75% post-2014, p<0.01). Overall, reporting adherence scores exceeded methodological adherence scores (74% vs. 60%, p<0.001). Articles seldom addressed budget impact (9% reporting, 10% methodological) or equity (7% reporting, 7% methodological). CONCLUSIONS: The iDSI reference case has substantial potential to serve as a useful resource for researchers and policy-makers in global health settings, but greater effort to promote adherence and awareness is needed to achieve its potential.