A Systematic Review of Economic Studies Evaluating Ophthalmic Drugs: An Analysis of the Health-state Utilities

Purpose To characterize the techniques used to derive health-state utilities (HSU) in the cost-utility studies (CUS) of ophthalmic drugs. Methods A systematic review was conducted in Pubmed/Embase until October 2019. CUS evaluating ophthalmic drugs were included. Therapeutic area, technique to derive HSU and sources of HSU were extracted. It was assessed if the HSU and the other parameters of CUS were collected from the same population. The techniques to derive HSU used in the CUS were compared to the techniques recommended by the country-specific economic evaluation guidelines. Results Seventy CUS were included. Forty-three (61.4%) used direct techniques to derive HSU, 19 (27.1%) used indirect, 1 (1.4%) used direct and indirect and the remaining (n = 7; 10.0%) used other or unknown techniques. Twelve (17.1%) CUS collected the HSU and the other parameters from the same population: nine (12.9%) retrieved utility data from experimental studies, two (2.9%) from observational and one (1.4%) from other sources. Forty-eight (68.6%) CUS collected the HSU and the other parameters from different populations: eight (11.4%) retrieved utility data from experimental studies, 33 (47.1%) from observational, one (1.4%) from both experimental and observational and six (8.6%) from other sources. It was not possible to identify the population from whom data were obtained in 10 (14.3%) CUS. Eleven (15.7%) CUS followed the recommendations of guidelines, 21 (30.0%) did not follow and for 38 (54.3%), it was not possible to assess. Conclusion Choosing different techniques to derive HSU may result in different results, which can preclude the comparison between cost-utility studies.