Psychometric Properties of Quality of Life Assessment Tools in Morbid Obesity: A Review of Literature

Background: Since studies have demonstrated that morbid obesity can exponentially impair quality of life, the measurement of quality of life is paramount to monitoring the effects of treatment and influences the development of clinical pathways, service provision, healthcare expenditures, and public health policy. Accordingly, clinicians, researchers, and policy makers must rely on valid instruments. Aim: This study aimed to review and critique the psychometric properties of some specific tools by COSMIN checklist and their application among morbidly obese individuals. Method: We searched PubMed, Web of Science, PsycINFO, Ovid, Elsevier, and ScienceDirect by using the keywords related to the Quality of Life Questionnaire, namely “morbid obesity”, “tool”, and “scale”, to retrieve articles published during 1989-2017. Then, the psychometric properties of the selected tools were assessed using the COSMIN checklist. Results: Most of the tools had not reported complete and desirable psychometrics properties. Demonstration of responsiveness from independent randomized controlled trials was not available in two of the eight questionnaires. These tools also did not report proper definition of interpretability. However, the data obtained by COSMIN checklist showed that Laval questionnaire is a proper scale for measuring quality of life in obese individuals, which can be recommended to researchers. Implications for Practice: Although Laval questionnaire was found a proper tool for measuring the quality of life among morbid obese patients, developing an instrument suitable for different societies with varied cultural and social characteristics is suggested because socio-cultural factors can influence the quality of life.