european crystal network workshop

    On the incidence of gout flares in primary care; a retrospective cohort study

    Background: From rheumatologist point of view (secondary care) there is a serious concern about suboptimal treatment of gout patients in the primary healthcare setting with warnings for worse prognostic consequence (1). Some refer even to a ‘state of suboptimal gout care’ promoted by “substantial gaps between rheumatologists and primary care providers” in their approaches to gout care (2):the former following the strategy of ‘treating-to-target’ (to lower serum uric acid (SUA) levels <0.36mmol/L), and the later of ‘treating-to-avoid-symptoms” (often without addressing hyperuricemia(3).Most studies on (suboptimal) gout care in the primary care setting checked patients for prescribed urate lowering treatment (ULT), SUA assessments or reached SUA target levels, omitting the major patient related clinical end point of gout, flare frequency(4).

    Objective: To quantify the occurrence of flares, together with use of ULT, in primary care patients with gout, and to analyze patient characteristics related to low or high flare frequency.

    Methods: A retrospective cohort study (setting one Dutch primary care center with an integrated medical praxis and pharmacy). Electronic medical records of ca. 5800 enlisted patients were used to select all patients with gout (diagnosis additionally validated), to analyze their ULT use, and to assess flare frequency in them during a 2-year time window (2014-2015). Flare was defined as each prescription and pharmacy delivery of an anti-inflammatory drug or pain killer linked to the International Classification of Primary Care morbidity code of gout. Associations were studied between high or low flare frequency and patient characteristics by univariate logistic regression.

    Results: Of 173 included patients (prevalence 3%; mean age 66.4 yr; 75.7% men) 38.7% used ULT persistently during the 2-year time-window. Median time after initial diagnosis was 8.0 yr (IQR 3.0-14.5). Mean total numbers of flares in two years was 2.7 (SD: 4.7), median 1.0 (IQR: 0.0-4.0). Of the patients not receiving ULT (n=106, 61.3%) 41.5% had never, 25.5% one or two, and 6.6% more than six flares during two years. No associations were found between patient characteristics (e.g. age, time after initial diagnosis, crystal proved diagnosis, ULT use, time window SUA level, cardiovascular co-morbidity, diuretic use) to differentiate patients with ‘no-or-1-flare’ and ‘2-or-more-flares’ per two years.

    Conclusion: Occurrence of flares in this stringently observed primary care cohort of patients with gout was very low, even if most patients did not use prophylactic ULT. Only a very small proportion of patients (6.6%) experienced more than six flares in two years. The presented patients, in particular those not using ULT and with a low flare frequency (the majority), may reflect individuals with a distinctive (moderate) disease activity. They probably do not fulfill the general accepted advancing course of gout with ongoing and increasing flare frequency, MSU deposition, tophus formation, and joint damage. Immediate (at the initial diagnosis) lifelong ULT for them may not be automatically indicated. Our study shows that suboptimal prophylactic gout management in the perception of rheumatologists (secondary care) does not lead to an abundant number of gout flares in primary care patients. This urges to caution when management recommendations based upon secondary care guide lines are advised for primary care patients with gout.