Sensitivity Analysis in Economic Evaluations of Immuno-Oncology Drugs: A Systematic Literature Review

Objectives: This study aimed to review, assess, and report the characteristics and strategies of sensitivity analyses (SAs) that were performed in the context of published economic evaluations of immuno-oncology drugs.Methods: The systematic literature search was conducted in Scopus and MEDLINE for articles published from 2005 to 2021. Study selection, based on a predefined set of criteria, was performed by 2 reviewers independently. We included economic evaluations of Food and Drug Administration-approved immuno-oncology drugs that were published in English and assessed the accompanying SAs on a set of items, including the range justification of the baseline parameters within the deterministic SA, the provisions for the correlation/overlay between parameters, and the justification of the chosen parameter distribution for the probabilistic SA, among others.Results: A total of 98 of 295 publications met the inclusion criteria. A total of 90 studies included a one-way and probabilistic SA and 16 of 98 studies had one-way and scenario analysis, alone or together with probabilistic analysis. Most studies provide explicit references as to the choice of parameters and values; nevertheless, there is a lack of a reference of correlation/overlay between parameters in most of the evaluations. In 26 of 98 studies, the most influential parameter for the incremental cost-effectiveness ratio was the under-evaluation drug cost.Conclusions: Most of included articles contained an SA that was implemented according to commonly accepted published guidance. The under-evaluation drug cost, the estimates of progression-free survival, the hazard ratio for overall survival, and the time horizon of the analysis seem to play an important part in the robustness of the outcomes.