Factors associated with change in health-related quality of life in people with gout: a 3-year prospective cohort study in primary care

OBJECTIVE: To describe factors associated with change in health-related quality of life (HRQOL) in people living with gout in primary care. METHODS: In a UK prospective cohort study, adults with a diagnosis of gout registered with 20 general practices completed the Gout Impact Scale (GIS; scale 0–100), 36-item Short Form Physical Function subscale (PF-10; 0–100) and HAQ Disability Index (HAQ-DI; 0–3) via postal questionnaires at baseline and 6, 12, 24 and 36 months. Linear mixed modelling was used to investigate factors associated with changes in HRQOL over 3 years. RESULTS: A total of 1184 participants responded at baseline (adjusted response 65.6%); 990 (83.6%) were male, with a mean age of 65.6 years (s.d. 12.5). A total of 818, 721, 696 and 605 responded at 6, 12, 24 and 36 months, respectively. Factors associated with worse disease-specific and generic HRQOL over 3 years were flare frequency (five or more flares; GIS subscales, PF-10), oligo/polyarticular flares (GIS subscales, PF-10, HAQ-DI), worse pain (GIS subscales, PF-10, HAQ-DI), body pain (GIS subscales, PF-10, HAQ-DI) and more severe depression (GIS subscales, PF-10, HAQ-DI) (P ≤ 0.05). More severe anxiety was associated with worse disease-specific HRQOL only (GIS subscales). Older age (PF-10), being female (PF-10, HAQ-DI) and BMI (HAQ-DI) were associated with worse generic HRQOL (P ≤ 0.05). CONCLUSION: Gout-specific, comorbid and sociodemographic factors were associated with change in HRQOL over a 3-year period, highlighting people at risk of worse outcomes who could be targeted for interventions.