Palpable tophi and more comorbidities associated with adherence to urate-lowering medical therapy in a Chinese gout cohort

Abstract

Objective: Urate-lowering therapy (ULT) nonadherence is common and problematic in gout. Since, sociocultural factors affect adherence, we analyzed a Chinese cohort.

Methods: We studied 903 Chinese gout patients aged 46.4±14.7 years (mean±SD), uniquely extending to assay of 2-year medication possession ratio (MPR) ≥80% defined as high adherence. Multivariable logistic regression analyses evaluated factors linked with adherence and ULT target attainment.

Results: Characterization of ULT outcomes in this cohort revealed that after 2 years ULT, MPR ≥80% patients had better target serum urate (SU) achievement (from 23.3% to 71.0%, P <0.001), lower flare frequency and palpable tophi compared to MPR <80%. However, only 44.7% of cohort subjects had MPR ≥80%. Male sex (OR 3.68), gout onset age >60 years (OR 3.51), disease duration >5 years (OR 1.70), more comorbidities (OR 1.74), baseline palpable tophi (OR 1.53), SU <6mg/dL (360μmol/L) (OR 1.92) and more frequent follow-up visits (OR 1.98) were significantly associated with high adherence. Nevertheless, significant independent risk factors for failed SU target achievement included male sex (OR 0.36) and more comorbidities (OR 0.85).

Conclusion: Despite adherence to ULT linked to better outcomes for flares and tophi, the more adherent Chinese male patients and those with more comorbidities had decreased target SU attainment. Differences in adherence of Chinese gout patients compared to several primarily Western studies emphasize the importance of not stereotyping gout patients for projected nonadherence. Results underline the dual importance of identifying gout patients more likely to be ULT-adherent and leveraging adherence to drive treatment to SU target.

Keywords: Adherence; Gout; Gout flare; Tophi; Urate-lowering therapy.