Background Gout is the most common inflammatory arthritic disease. Treatment has been available since the 1950's and studies from different countries have demonstrated insufficient treatment with urate lowering therapy (ULT); however, contemporary data are scarce.
Objectives The aims of the present observational registry study were to determine; 1) the proportion of patients receiving ULT after gout diagnosis and predictors thereof, and 2) the proportion of patients stopping ULT temporarily and predictors thereof.
Methods All incident cases of patients with gout in the Western Swedish Health Care Region (WSHCR) during 2005–2013, age ≥18 years, were identified in the healthcare consumption database VEGA. WSHCR covers approximately 20% of the total Swedish population. Incident case of gout was defined as a visit with gout diagnosis (ICD-10-CM M10, M14.0–14.1), not preceded by a gout diagnosis during the previous 12 months. First dispense of ULT (allopurinol, febuxostat and probenecid) was identified in the Swedish Prescribed Drug Register. Age, comorbidities (ischemic heart disease, cardiac arrhythmias, congestive heart failure, peripheral vascular disease, cerebrovascular disease, COPD and diabetes), renal disease and renal function (calculated eGFR based on demographics and serum-creatinine), at time of gout diagnosis and at time of first ULT dispensation, were identified in VEGA. Temporary ULT stop was defined as no collection of ULT within 125 days from last dispense. Two binary outcomes were addressed: (i) receiving ULT within 30 days since diagnosis and (ii) temporary ULT stop 125 days after first ULT dispensation. The effects of sex, age, comorbidity, renal disease and renal function, respectively, were estimated by logistic regression. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.
Results In total, 18 404 incident cases of gout were identified, whereof 4107 (22.3%) and 6272 (34.08%) received ULT within 30 days and 365 days post-diagnosis, respectively (Fig 1a-b). Male sex, age ≥60, reduced kidney function by eGFR, presence of renal disease and presence of ≥1 comorbidities all moderately but significantly (p<0.05) predicted receiving ULT within 30 days (Fig 1a-b). 7165 (39%) of the cases were followed-up after their first ULT dispense (not necessarily within 30 days since diagnosis) and 2809 (39.2%) and 4670 (65.18%) had a temporary stop in the ULT treatment after 125 and 365 days, respectively (Fig 1c-d). The odds of a temporary stop was significantly (p<0.05) but moderately predicted by male sex, age <60, normal kidney function by eGFR, non-presence of renal disease and total lack of comorbidities (Fig 1c-d). The likelihood of starting or temporary stopping ULT did not significantly change during the study period (data not shown)
Conclusions We found that only a minority of patients started ULT within one year after gout diagnosis, and the majority of these stopped therapy within one year. Age, renal disease and other comorbidities only moderately improved these results. Thus, there is still room for considerable improvement with regard to ULT in the treatment of gout.
Disclosure of Interest None declared