In Europe, adult immune thrombocytopenia (ITP) has an incidence of 1.6 to 3.9 cases in 100,000 per year.[4]Terrell DR, Beebe LA, Vesely SK, et al. The incidence of immune thrombocytopenic purpura in children and adults: a critical review of published reports. Am J Hematol. 2010 Mar;85(3):174-80.
https://onlinelibrary.wiley.com/doi/abs/10.1002/ajh.21616
http://www.ncbi.nlm.nih.gov/pubmed/20131303?tool=bestpractice.com
Incidence increases with older age and there is a higher female-to-male ratio (3:1) in younger patients. A nationwide population study in the UK reported a crude incidence of 3.9 cases in 100,000 person-years, with a higher incidence in women.[5]Schoonen WM, Kucera G, Coalson J, et al. Epidemiology of immune thrombocytopenic purpura in the General Practice Research Database. Br J Haematol. 2009 Apr;145(2):235-44. [Erratum in: Br J Haematol. 2009 Sep;147(1):157.]
https://onlinelibrary.wiley.com/doi/full/10.1111/j.1365-2141.2009.07615.x
http://www.ncbi.nlm.nih.gov/pubmed/19245432?tool=bestpractice.com
A nationwide population study in France reported an incidence of 2.9 cases (of ITP necessitating health care) in 100,000 per year.[6]Moulis G, Palmaro A, Montastruc JL, et al. Epidemiology of incident immune thrombocytopenia: a nationwide population-based study in France. Blood. 2014 Nov 20;124(22):3308-15.
http://www.bloodjournal.org/content/124/22/3308.long
http://www.ncbi.nlm.nih.gov/pubmed/25305203?tool=bestpractice.com
ITP was secondary to other disease in 18% of cases.[6]Moulis G, Palmaro A, Montastruc JL, et al. Epidemiology of incident immune thrombocytopenia: a nationwide population-based study in France. Blood. 2014 Nov 20;124(22):3308-15.
http://www.bloodjournal.org/content/124/22/3308.long
http://www.ncbi.nlm.nih.gov/pubmed/25305203?tool=bestpractice.com
Childhood ITP has an incidence of between 1.9 and 6.4 in 100,000 per year with equal distribution between the sexes, and tends to result in spontaneous remission.[4]Terrell DR, Beebe LA, Vesely SK, et al. The incidence of immune thrombocytopenic purpura in children and adults: a critical review of published reports. Am J Hematol. 2010 Mar;85(3):174-80.
https://onlinelibrary.wiley.com/doi/abs/10.1002/ajh.21616
http://www.ncbi.nlm.nih.gov/pubmed/20131303?tool=bestpractice.com
Data on epidemiology from the US and other countries is lacking. One study of two US private healthcare claims databases from 2012 to 2015 estimated an annual incidence of 6.1 cases per 100,000 population. Incidence was higher for women (6.7 per 100,000) than for men (5.5 per 100,000), and highest in children ages 0-4 years (6.1 per 100,000) and adults ages ≥65 years (13.7 per 100,000).[7]Weycker D, Hanau A, Hatfield M, et al. Primary immune thrombocytopenia in US clinical practice: incidence and healthcare burden in first 12 months following diagnosis. J Med Econ. 2020 Feb;23(2):184-92.
https://www.tandfonline.com/doi/full/10.1080/13696998.2019.1669329
http://www.ncbi.nlm.nih.gov/pubmed/31547724?tool=bestpractice.com
The prevalence of ITP has been estimated as between 9.6 and 20.0 in 100,000 in the US, based on insurance administrative data, with higher prevalence with increasing age and among female adults.[8]Segal JB, Powe NR. Prevalence of immune thrombocytopenia: analyses of administrative data. J Thromb Haemost. 2006 Nov;4(11):2377-83.
https://onlinelibrary.wiley.com/doi/full/10.1111/j.1538-7836.2006.02147.x
http://www.ncbi.nlm.nih.gov/pubmed/16869934?tool=bestpractice.com
[9]Feudjo-Tepie MA, Robinson NJ, Bennett D. Prevalence of diagnosed chronic immune thrombocytopenic purpura in the US: analysis of a large US claim database: a rebuttal. J Thromb Haemost. 2008 Apr;6(4):711-2;author reply 713.
https://www.jthjournal.org/article/S1538-7836(22)10558-1/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/18221355?tool=bestpractice.com