Incidence of immune thrombocytopenia in Taiwan: a nationwide population‐based study

Abstract

BACKGROUND The incidence of immune thrombocytopenia (ITP) is not well known in Asians. The aims of this study were to survey incidences and clinical features of ITP in Taiwan. STUDY DESIGN AND METHODS This study identified 4855 incident ITP cases from the population‐based National Health Insurance Research Database from mid‐2006 to mid‐2013, and compared incidences, patient characteristics, and clinical manifestations of ITP by age. RESULTS Respective ITP incidence rates among those aged <15, 15 to 59, and ≥60 years were 4.0, 2.0, and 5.4 per 100,000 person‐years. A male predominance was noted in children, and a female predominance was found in adults. The most common causes of secondary ITP were systemic lupus erythematosus (21.8%), viral hepatitis C (16.9%), and viral hepatitis B (13.4%). The rate of secondary ITP in children was less than one fifth that in adults (4.2% vs. 23.8%). Rates of central nervous system (1.1%) and gastrointestinal tract bleeding (3.3%) were rare, with variations by age. The rate of splenectomies in children (0.4%) was only one tenth that in adults (4.1%). The disease in 25% of children and 30% of adults became persistent or chronic. A decreasing trend in the ITP incidence was found (annual percentage change, −4.9%), and it was confined to those aged >15 years. CONCLUSION Incidence estimates of ITP in Taiwan were close to those of Western countries, with age‐specific variations in sex ratio, comorbidity, splenectomy, secondary causes, and incidence trends. The results suggest no racial variations in ITP incidences, but a geographical difference in causes of secondary ITP.

Chronic immune thrombocytopenia in Denmark, Sweden and Norway: The Nordic Country Patient Registry for Romiplostim

“…In Japan, the reported incidence rate of ITP was 2 · 16 per 100,000 person-years among patients with a platelet count < 100 × 10 9 /L. [7] In Korea and Taiwan the incidence of diagnosed ITP in adults has been reported to be 3 · 7, 2 · 9 and 2 · 59 per 100,000 person-years, respectively [8], [9], [10].…”

“…Primary immune thrombocytopenia (ITP) is a rare autoimmune disorder that leads to decreased production and peripheral destruction of platelets [1]. Incidence of ITP in adults ranged from 1 · 6 to 3 · 9 per 100,000 person-years in previous studies conducted in Denmark, Sweden, France, Japan, Korea, Taiwan, and the United Kingdom (UK) [2], [3], [4], [5], [6], [7], [8], [9], [10]. Prevalence of ITP was reported to be between 4 · 5 and 23 · 6 per 100,000 persons in two US studies [11], [12].…”

Incidence and prevalence of immune thrombocytopenia under the copayment waiver policy for pediatric patients in Korea: Data from the National Health Claims Database

“…5,10 The incidence was also higher than in USA and western countries (2.8–8.8 per 100,000 persons), 8,11,15 and in Asian country, Taiwan (4.0 per 100,000 persons). 6 An earlier Korean study showed similar results (14.3 per 100,000 persons). 7…”

“…In many studies of ITP, similar patterns were seen, such that the proportions of patients were higher in the younger children group, and the peaks were observed in children of one to four-year-old with ITP. 6,15,18…”

“…Although previous nationwide population-based or cohort studies of ITP demonstrated higher rates in children than adults, ITP data was often only reported on indirectly as a subset of adult ITP epidemiological data, and categorized by age based on 5- or 10-year intervals. 5–12…”