Patients with gout treated with conventional urate-lowering therapy: Association with disease control, health-related quality of life, and work productivity

Abstract

Objective. Implications of inadequate gout control were assessed through health-related quality of life (HRQOL) and work productivity of patients with gout adequately controlled while taking conventional urate-lowering therapy (ULT) for ≥ 3 months vs those whose gout was inadequately controlled. Methods. Retrospective data were drawn from the Adelphi Disease Specific Programme (DSP), a cross-sectional survey of patients with gout in France, Germany, the United Kingdom, and the United States. Patients completed these questionnaires: EQ-5D (3L), Patient Reported Outcomes Measurement Information System (PROMIS) Health Assessment Questionnaire (HAQ), and Work Productivity and Activity Impairment. Inadequate control was defined as the most recent serum uric acid (SUA) level > 6 mg/dl (> 360 μmol/l) or ≥ 2 flares in the last 12 months; adequate control as SUA level ≤ 6 mg/dl (≤ 360 μmol/l) and 0 flares. Appropriate statistical tests were used to assess differences between groups. Results. There were 836 (69%) inadequately and 368 (31%) adequately controlled gout cases. Mean age was 61 and 63 years and duration of current ULT was 32 and 57 months, respectively. Patients experiencing inadequate control reported significantly worse functioning and HRQOL, as measured by the EQ-5D (0.790 vs 0.877; difference: -0.087; p < 0.001) and PROMIS HAQ (13.21 vs 6.91; difference: 6.30; p < 0.001) scales. Productivity was also more impaired (work time missed: 4.5% vs 1.3%; impairment while working: 19.1% vs 5.2%; overall work impairment: 20.4% vs 5.6%; activity impairment: 20.3% vs 5.3%; all p < 0.001). Conclusion. Less than one-Third of patients had gout that was adequately controlled. Those experiencing inadequately controlled gout reported significantly worse functioning, quality of life, and work productivity. Gout treatment strategies to improve disease control may lead to improvements in HRQOL and productivity.