Remission in gout is possible: 5-year follow-up in the NOR-Gout study

OBJECTIVE: To compare the performance of remission definitions for gout in an observational treat-to-target patient cohort with 5 years of follow-up. METHODS: Inclusion criteria were crystal proven gout with increased serum urate levels and a flare. Remission was determined according to the 2016 preliminary gout remission definition, a modified preliminary definition with more lenient thresholds for the individual variables pain due to gout and patient global assessment of gout disease activity, and the simplified definition without patient reported outcomes. Linear mixed models were used to compare quality of life with SF-36 physical (PCS) and mental (MCS) components and structural damage with semiquantitative dual energy tomography (DECT) across patients fulfilling and not fulfilling each remission definition. RESULTS: Data were analysed from 211 patients (mean age 56.4 years, 95.3 % males) included in an intensive one-year treat-to-target intervention with follow-up at 1, 2, and 5 years. The frequency of remission increased for both the preliminary definition at 1, 2 and 5 years (4.6 %, 22.1 %, and 42.8 %), the modified preliminary definition (5.1 %, 28.4 %, and 44.1. %) and the simplified definition (7.7 %, 45.4 %, and 58.6 %)(p < 0.001 for all definitions). The simplified definition identified more patients in remission than the preliminary and the modified preliminary definition at years 2 and 5. All three definitions discriminated for SF-36 MCS, PCS or DECT. CONCLUSION: Remission in gout after urate lowering therapy was seldom after 1 but high after 5 years and was highest for the simplified definition. Remission definitions showed concurrent validity for quality of life and structural changes.