Agreement Among Paper and Electronic Modes of the EQ-5D-5L

While the EQ-5D-5L has been migrated to several electronic modes, evidence supporting the measurement equivalence of the original paper-based instrument to the electronic modes is limited.

This study was designed to comprehensively examine the equivalence of the paper and electronic modes (i.e., handheld, tablet, interactive voice response [IVR], and web).

As part of the foundational work for this study, the test-retest reliability of the paper-based, UK English format of the EQ-5D-5L was assessed using a single-group, single-visit, two-period, repeated-measures design. To compare paper and electronic modes, three independent samples were recruited into a three-period crossover study. Each participant was assigned to one of six groups to account for order effects. Descriptive statistics, mean differences (i.e., split-plot analysis of variance [ANOVA]), and intraclass correlation coefficients (ICCs) were calculated.

The test-retest results showed mean differences near zero and ICC values > 0.90 for both the index and the EQ VAS scores. For the electronic comparisons, mean difference confidence intervals (CIs) for the EQ-5D index scores and EQ VAS scores reflected equivalence of the means across all modes, as the CIs were wholly contained inside the equivalence interval. Further, the ICC 95% lower CIs for the index and EQ VAS scores showed values above the thresholds for denoting equivalence across all comparisons in each sample. No significant mode-by-order interactions were present in any ANOVA model.

Overall, our comparisons of the paper, screen-based, and phone-based formats of the EQ-5D-5L provided substantial evidence to support the measurement equivalence of these modes of data collection.