Keele Research Repository

OBJECTIVE: To investigate associations between treat-to-target urate-lowering therapy (ULT) and hospitalisations for gout.

METHODS: Using linked Clinical Practice Research Datalink and NHS Digital Hospital Episode Statistics data, we described the incidence and timing of hospitalisations for flares in people with index gout diagnoses in England from 2004-2020. Using Cox proportional hazards and propensity models, we investigated associations between ULT initiation, serum urate target attainment, colchicine prophylaxis, and the risk of hospitalisations for gout.

RESULTS: Of 292 270 people with incident gout, 7,719 (2.64%) had one or more hospitalisations for gout, with an incidence rate of 4.64 hospitalisations per 1000 person-years (95% CI 4.54-4.73). There was an associated increased risk of hospitalisations within the first 6 months after ULT initiation, when compared with people who did not initiate ULT (adjusted Hazard Ratio (aHR) 4.54; 95% CI 3.70-5.58; p< 0.001). Hospitalisations did not differ significantly between people prescribed vs. not prescribed colchicine prophylaxis in fully-adjusted models. From 12 months after initiation, ULT associated with a reduced risk of hospitalisations (aHR 0.77; 95% CI 0.71-0.83; p< 0.001). In ULT initiators, attainment of a serum urate <360 micromol/l within 12 months of initiation associated with a reduced risk of hospitalisations (aHR 0.57; 95% CI 0.49-0.67; p< 0.001) when compared with people initiating ULT but not attaining this target.

CONCLUSION: ULT associates with an increased risk of hospitalisations within the first 6 months of initiation but reduces hospitalisations in the long-term, particularly when serum urate targets are achieved.