Measurement Properties of the EQ VAS Around the Globe: A Systematic Review and Meta-Regression Analysis

ObjectivesThis study aimed to synthesize and evaluate published evidence on the measurement properties of the EQ VAS, a component of all EQ-5D questionnaires.MethodsThis systematic review followed the Consensus-Based Standards for the Selection of Health Measurement Instruments guidelines. Five electronic databases were searched for EQ-5D-3L and EQ-5D-5L validation articles published from January 1, 2009, to November 5, 2019. Evidence for construct validity, test–retest reliability, and responsiveness was extracted from individual studies before being aggregated for evaluation of the populations represented by the studied samples. Multivariable logistic meta-regression was conducted to explore the effects of potential covariates on construct validity.ResultsA total of 50 articles containing 488 studies, using samples drawn from 12 different populations, were identified. Generally, the quality of evidence was high for construct validity studies (n = 397) but only moderate for both test–retest reliability studies (n = 21) and responsiveness studies (n = 70). “Sufficient” construct validity of EQ VAS was found in 8 of 12 populations, “sufficient” test–retest reliability was found in 3 of 11 populations, and “sufficient” responsiveness was found in 5 of 12 populations. Meta-regression analyses suggested that construct validity studies from the Asian-Pacific region were more likely to show a negative rating compared with studies from Europe and North America.ConclusionThe EQ VAS exhibits “sufficient” construct validity, “inconsistent” test–retest reliability, and “inconsistent” responsiveness across a broad range of populations. Additional studies are needed to explore the suboptimal validity of the EQ VAS in the Asian-Pacific region, whereas more high-quality validation studies are needed to assess its reliability and responsiveness.