Impact of Question Wording on the Measurement of Activity Limitation: Evidence From a Randomized Test in France

Objective: The Global Activity Limitation Indicator (GALI), a single question measuring disability, had been introduced in various European surveys since 2004. The complexity of its wording has been questioned. Our study compares alternative variants aiming to simplify the wording. Method: We used the Health-Related Opinion Survey run in 2014 in France (N = 3,009). Its split sample design allows testing four variants of the questions. We analyzed the prevalence of activity limitation (AL) resulting from the four different constructs of the GALI using multinomial logistic regressions, adjusted for background variables and functional limitations (FLs). Results: The alternative GALI variants result in significantly different prevalences compared with the original question, in particular for people with FL. The current variant is more inclusive than the routed variants. Discussion: Our study suggests limited benefits of changing the GALI construct which do not outweigh the costs of breaking the established chronological series of the current variant.