Use of health-related quality of life in prescribing research. Part 2: methodological considerations for the assessment of health-related quality of life in clinical trials.

This article aims to address key methodological issues that should be considered when assessing health-related quality of life (HRQoL) in a clinical trial. These include justification for the selection of HRQoL as a primary or secondary outcome and choice of an appropriate instrument to assess HRQoL, which meets basic psychometric properties. In addition we consider ways to minimize bias within the trial through optimization of compliance and timing of assessments.