Objectives: To identify the instruments that have been used to measure health-related quality of life (HRQOL) in gout and assess their clinimetric properties, determine the distribution of HRQOL in gout and identify factors associated with poor HRQOL.
Methods: Medline, CINAHL, EMBASE and PsycINFO were searched from inception to October 2012. Search terms pertained to gout, health or functional status, clinimetric properties and HRQOL. Study data extraction and quality assessment were performed by two independent reviewers.
Results: From 474 identified studies, 22 met the inclusion criteria. Health Assessment Questionnaire Disability Index (HAQ-DI) and Short Form 36 (SF-36) were most frequently used and highest rated due to robust construct and concurrent validity, despite high floor and ceiling effects. The Gout Impact Scale had good content validity. Gout had a greater impact on physical HRQOL compared to other domains. Both gout-specific features (attack frequency and intensity, intercritical pain and number of joints involved) and comorbid disease were associated with poor HRQOL. Evidence for objective features such as tophi and serum uric acid was less robust. Limitations of existing studies include cross-sectional design, recruitment from specialist clinic settings and frequent use of generic instruments.
Conclusion: Most studies have used the generic HAQ-DI and SF-36. Gout-specific characteristics and comorbidities contribute to poor HRQOL. There is a need for a cohort study in primary care (where most patients with gout are treated) to determine which factors predict changes in HRQOL over time. This will enable those at risk of deterioration to be identified and better targeted for treatment.
Keywords: clinimetrics; gout; health-related quality of life.