Impact of Weight on Quality-of-Life Questionnaire-Lite, Mexican Version. Reliability and Validity Evidence

Abstract

The short form of the Impact of Weight on Quality of Life (IWQOL) is a 31-item self-report, that assesses the influence of weight on life quality in five areas: physical function, self-esteem, sexual life, public distress, and work. The objective of this study was to assess reliability and validity of the instrument in Mexican adults with weight ranging from normal to obese. Participants were 211 women and 98 men recruited from a public university. During a pre-scheduled appointment their weight and high were measured (average BMI = 26.13). Same participants were e-mailed the IWQOL-Lite, and the collateral measure questionnaires: DASS-21, TFEQ-R18, and a Physical Activity item. Internal consistency of the IWQOL-Lite total scale and subscales ranged from α = .82 to .95. The five-factor structure was confirmed with the number of items reduced to 26 via confirmatory factor analysis. Evidence of the convergent validity was obtained via correlations with the above-mentioned collateral measures. Our findings suggest that IWQOL-Lite (26 items) is a psychometrically valid measure that discriminates between different BMI groups and can be used to evaluate the impact of weight in the population of Mexican adults.