Systematic review of the factor structure of WHOQOL-bref in adult population

The WHOQOL-bref is a widely used instrument for assessing quality of life in adults, demonstrating robust psychometric properties and cross-cultural validation. While numerous studies support its original four-domain structure, others propose alternative models. This systematic review aims to compile the available evidence on its factor structure in the adult population and provide recommendations for its application.

Following PRISMA guidelines, the COSMIN’s Risk of Bias Checklist (structural validity module) was used to assess risk of bias. Searches were conducted in PubMed, PsycINFO, and Scopus, including articles in English, Spanish, or Portuguese published between January 2000 and May 2024. Studies were selected if they involved adults, were peer-reviewed, included factor analysis (FA), and reported model fit indices. The analysis considered sample characteristics, type of FA, number of factors, and model fit.

439 articles were identified, and 36 were included. The year with the most publications was 2018 (14%), and Taiwan was the most represented country (11%). Among the studies, 31% analyzed populations with specific health conditions, and 58% had a female predominance. In 64% of the studies, four factors were consistently identified. Several variable structures (ranging from three to eight factors) were observed, depending on the type of FA used.

The original four-factor model of the WHOQOL-bref has been confirmed. However, some studies suggest modifications to its structure depending on contextual, cultural, and clinical factors. Key limitations include a lack of standardization in methodological criteria and inconsistent reporting of fit indices.