THU0426 Long-term adherence to urate-lowering therapy in gout: do not blame on the patients

Abstract

Background: adherence to urate‐lowering treatment (ULT) in patients with gout is reported to be lower than 50% in the first year, below 20% at 2‐year, and worse than in other chronic conditions such as hypertension, diabetes, or hyperlipidemia. Objectives: to evaluate adherence to ULT both overall and during follow‐up, to compare it to the adherence to medications for associated comorbidities, and to explore potential causes for non‐adherence to ULT. Methods: transversal study of a nested cohort of patients in a gout clinic in the hospital setting who were scheduled for a follow‐up visit during 6 consecutive months in 2016. General data of patients, along with variables related to gout and to comorbid conditions are systematically retrieved at first visit; prescribed ULT, doses, adherence, and serum urate levels were obtained during the follow‐up visits. Adherence was retrieved as medication possession rate (MPR) according to pharmacy offices from government electronic databases (including >98% of the general population). Also, MPRs of drugs prescribed for hypertension, diabetes (only oral), and hyperlipidemia were obtained; if more than one drug prescribed for any of the previous, the best adherence per comorbidity treatment was entered. Good adherence was considered as MPR>80 percent of that prescribed, target serum urate (sUA) as <0.36 mmol/L. Patients are educated at first visit and encouraged to be adherent from baseline through follow‐up visits. Results: adherence data were available from 209 patients who were scheduled for a follow‐up visit during the observation period; 14 (6.7%) patients did not atend the visit. This sample was formed by 90% male, only 55% had received ULT previous to first visit, median age was 65 years at follow‐up visit, 47% and 44% showed poliarticular and tophaceous disease at baseline, respectively. MPR overall showed a median of 89% (IQR 79‐94, N=209) for ULT (72% had MPR>80), and 89% (IQR 81‐94, N=119), 88% (IQR 79‐94, N=65), and 82% (IQR 77‐93, N=28) for hypertension, hyperlipidemia, and diabetes respectively (p<0.05 only for diabetes). Adherence was lower for patients who did not attend the scheduled visit (median MPR 58% vs. 86%, MPR >80, 21% vs. 75%, p<0.01). Adherence was lower during the first year (80%, N=67) compared to 2nd and 3rd year period (86%, N=67) or 4 year or over (89%, N=75). MPR>80 was 57%, 76% y 81% for the same periods of follow‐up, respectively. Good adherence was associated to a rate of target serum urate of 90%, compared to 72% for patients showing MPR<80. Male gender and un‐attendance to scheduled visit were statistically associated to MPR<80 in multivariate analysis, and numerically to increasing age and overall comorbidity. Conclusions: adherence to ULT measured as MPRs in a cohort of educated patients is good, sustained during follow‐up, and similarly good to that for comorbid conditions (hypertension, hyperlipidemia, and diabetes); therefore, we cannot blame poor adherence on the patients anymore. Targeting absenteeism could be an opportunity for further improvement.