Prevalence of Diagnosed Adult Immune Thrombocytopenia in the United Kingdom

Data regarding the prevalence of immune thrombocytopenia (ITP) is limited, and is derived from North American population-based analyses. Therefore, the authors conducted the first study outside the United States (US) using the United Kingdom (UK) General Practice Research Database (GPRD) to estimate the adult prevalence of ITP in the UK.This study estimated the diagnosed prevalence of ITP in the adult population in UK using the GPRD from January 1, 1992 to December 31, 2009.The unadjusted, overall 18-year period prevalence was 50.29/100,000 (95% CI: 48.51, 52.06). The age- and gender-adjusted, overall 18-year period prevalence was 50.00/100,000 (95% CI: 49.20, 50.90). ITP prevalence was lower in adults aged 18-49 years of age (30.09/100,000, 95% CI: 28.27, 31.90) than in older adults aged 50-64 years of age (58.22/100,000, 95% CI: 53.88, 62.57) or ≥65 years of age (93.80/100,000, 95% CI: 88.76, 98.85). Prevalence was higher among females (59.32/100,000, 95% CI: 56.63, 62.01) than in males (40.66/100,000, 95% CI: 38.36, 42.96). Prevalence in the GPRD increased over time (1992 [16.33/100,000, 95% CI: 13.70, 19.00], 2000 [36.93/100,000, 95% CI: 34.50, 39.30], and 2009 [58.49/100,000, 95% CI: 55.80, 61.20]).This new analysis of general practice in the UK provides robust prevalence estimates of diagnosed ITP among adults in Europe. ITP prevalence is higher in women and increases with age and over time.