Contemporary epidemiology of gout in the UK general population

Abstract

Introduction: The objective of this study was to investigate the contemporary incidence of gout, examine potential risk factors, and evaluate specific gout treatment patterns in the general population.

Methods: Using the health improvement network (THIN) UK primary care database, we estimated the incidence of gout based on 24,768 newly diagnosed gout patients among a cohort of 1,775,505 individuals aged 20 to 89 years between 2000 and 2007. We evaluated potential risk factors for incident gout in a nested case-control study with 50,000 controls frequency-matched by age, sex and calendar time. We calculated odds ratios (OR) by means of unconditional logistic regression adjusting for demographic variables, lifestyle variables, relevant medical conditions and drug exposures.

Results: The incidence of gout per 1,000 person-years was 2.68 (4.42 in men and 1.32 in women) and increased with age. Conventional risk factors were significantly and strongly associated with the risk of gout, with multivariate ORs of 3.00 (95% confidence interval (CI)) for excessive alcohol intake (that is, more than 42 units per week), 2.34 (95% CI 2.22 to 2.47) for obesity (body mass index > = 30 kg/m2), 2.48 (95% CI 2.19 to 2.81) for chronic renal impairment, and 3.00 (95% CI 2.85 to 3.15) for current diuretic use. For other medical conditions the multivariate OR were 1.84 (95% CI 1.70 to 2.00) for heart failure, 1.45 (95% CI 1.18 to 1.79) for hypertriglyceridemia and 1.12 (95% CI 1.04 to 1.22) for psoriasis. Use of cyclosporine was associated with an OR of 3.72 (95% CI, 2.17 to 6.40). Among gout-specific therapies, allopurinol was the most frequently used with a one-year cumulative incidence of 28% in a cohort of incident gout diagnosed from 2000 to 2001. Use of gout-specific treatment has not changed over recent years except for an increase of colchicine.

Conclusions: The contemporary incidence of gout in UK remains substantial. In this general population cohort, associations with previously purported risk factors were evident including psoriasis, heart failure, hypertriglyceridemia, and cyclosporine therapy. Use of gout-specific treatment has remained relatively constant in recent years except for an increase of colchicine.

Figure 1

Sex and age specific incidence rate of gout 2000 to 2007 in the THIN database. Incidence rates per 1,000 person-years: overall 2.68 (95% CI 2.65 to 2.72), men 4.42 (95% CI 4.36 to 4.48), women 1.32 (95% CI 1.29 to 1.35)

Figure 2

Sex and age specific incidence rate of gout in 2000/2001 and 2006/2007. 2000 to 2001: Incidence rates per 1,000 person-years: overall 2.67 (95% CI 2.59 to 2.75), men 4.48 (95% CI 4.33 to 4.64), women 1.28 (95% CI 1.21 to 1.35). 2006 to 2007: Incidence rates per 1,000 person-years: overall 2.52 (95% CI 2.46 to 2.57), men 4.01 (95% CI 3.91 to 4.12), women 1.25 (95% CI 1.20 to 1.30).

Figure 3

Cumulative incidence of gout treatment over gout disease duration.

Figure 4

One-year cumulative incidence of gout treatment in 2000 to 2001 and 2006 to 2007.