Fig. 2.

Key comments and regulatory decision on PRO results. The key comments extracted from the clinical review documents were categorised and shown on the top of the figure. Study designs of the pivotal trials supporting each drug approval were colour-coded and indicated on the left of the figure. FDA's decisions on PRO results were indicated by a symbol after the established name of listed products. A circle indicated that the PRO result was not considered part of the efficacy benefit evidence but were considered as important data for the review of safety and tolerability, and a star indicated that it supported efficacy benefit and was included in the original labelling. The absence of a circle or a star indicated that the PRO results were not endorsed by the FDA. Issues that were not addressed by the FDA reviewers could also exist in the related studies. Abbreviations: FDA, US Food and Drug Administration; MCID, minimal clinically important difference; PROM, patient-reported outcome measures.