The worldwide prevalence of psoriatic arthritis-a systematic review and meta-analysis.

OBJECTIVES: Previous attempts to pool prevalence studies in PsA have failed to take account of important methodological differences between studies which may have created biased estimates. The aim of this review is to estimate the prevalence of PsA within the adult general population worldwide, considering potential differences between population-based and health administrative studies separately.

METHODS: Four electronic databases were systematically searched for articles reporting the prevalence of PsA. Data were pooled to generate worldwide prevalence estimates. Where sufficient data were available, results were summarised by continent.

RESULTS: 30 studies were identified, with half from Europe (n = 15). Thirteen population-based studies were identified comprising >92 000 adults, plus 17 studies (>180 million adults) based on health administrative data. The worldwide prevalence of PsA was 112 per 100 000 adults. The prevalence of PsA estimated using populations-based studies was 113 per 100 000 with continent-specific estimates of 207 (Europe), 64 (North America), and 37 (Asia) per 100 000. Health administrative studies gave a global prevalence of 109 per 100 000 with continent-specific prevalence of 175 (Europe), 147 (North America), 78 (Asia), and 17 (South America).

CONCLUSION: This review compiles currently available estimates of PsA prevalence in the general population into global and continent-based estimates and considers important study design characteristics. There is wide variability between continents and data in some geographical areas are sparse but available evidence suggests that PsA is more common in Europe and North America compared with Asia and South America, and current best estimates suggest a global prevalence of 112 per 100 000 adults.