Measuring Health-Related Quality of Life in Randomised Controlled Trials: Expected and Reported Results Do Not Match

The assessment of health-related quality of life (hrQoL) may need to be reconsidered due to important differences between efficacy (the effect of a treatment under experimental study conditions) and effectiveness (the effect of a treatment under real-world conditions). We presume that most researchers intend to describe effects under real-world conditions when investigating hrQoL as an endpoint. Unfortunately, most studies are designed to confirm two theories: the efficacy of a new intervention under experimental study conditions and the real-world effectiveness of this intervention on hrQoL under non-experimental study conditions. Conflicting information emerges when the outcomes are supposed to describe effects under real-world conditions, but the assessment generates results obtained under experimental conditions. This paper examines the existing conflict between efficacy and effectiveness in a sample of 100 studies investigating hrQoL.