Development of a clinical trials version of the Impact of Weight on Quality of Life-Lite questionnaire (IWQOL-Lite Clinical Trials Version): Results from two qualitative studies: IWQOL-Lite Clinical Trials Version

What is already known about this subject • Obesity is widely studied in clinical trials, perhaps due to its extremely high prevalence worldwide. • Health-related quality of life (HRQOL) and patient functioning are important secondary end points in clinical trials. • Existing measures of HRQOL and patient functioning, such as the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) questionnaire, lack the developmental rigour required by the Food and Drug Administration (FDA) to support product labelling. What this study adds • An alternative version of the IWQOL-Lite questionnaire has been developed and refined through two qualitative studies involving 71 patients. • The IWQOL-Lite Clinical Trials Version consists of a comprehensive set of items optimized for use in a patient population typically targeted for obesity clinical trials. • Ultimately, it is anticipated that the final measure will be qualified by the FDA for use in clinical trials of new weight-loss medications to support product approval and labelling claims.