Gout in Dalarna, Sweden - a population-based study of gout occurrence and compliance to treatment guidelines

Objective This study aimed to describe the incidence and prevalence of gout, describe the use of allopurinol among prevalent gout cases, and determine persistence with allopurinol and degree of compliance with treat-to-target recommendations before and after the publication of Swedish national guidelines in 2016. Method Prospectively registered data on gout diagnoses and allopurinol prescriptions were used to calculate incidence and prevalence, and the proportion of prevalent patients on allopurinol. Gout patients starting allopurinol during 2013-2015 versus 2016-2018 were compared regarding persistence and compliance with treat-to-target principles. Results The incidence of gout was 221-247 per 100 000 person-years during 2014-2019, prevalence in 2018 was 2.45%. Among prevalent cases, the proportion on allopurinol ranged from 21% to 25%. Allopurinol persistence was better for individuals starting therapy during 2016-2018 compared with 2013-2015 (45% vs 39%, p = 0.031), as were several outcomes related to treat-to-target principles, e.g. measuring baseline serum urate (SU) (84% vs 77%, p < 0.001), follow-up SU (50% vs 36%, p < 0.001), and the proportion of patients reaching an SU level < 360 mu mol/L (45% vs 30%, p < 0.001). Conclusion Incidence and prevalence were slightly higher than in previous Swedish reports. Allopurinol use among prevalent gout patients did not increase during 2014-2019. Only a minor improvement in persistence was seen, and a moderate increase in compliance with guidelines, suggesting a need for improved management and extended patient involvement to increase and optimize the use of urate lowering therapy.