Vitreous haemorrhage: a population-based study of the incidence and risk factors in Taiwan

To report the epidemiology and incidence of vitreous hemorrhage and to evaluate risk factors for patients with vitreous hemorrhage (VH) in Taiwan.

A retrospective population-based study. Analyzing a sample of one million subjects from all enrollees of the Taiwan Health Insurance programme. All data were obtained from the Taiwan Health Insurance Research Database, which contained patient sex, date of birth, all records of clinical visits and hospitalizations, and diagnosis codes as included in the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). The main outcome measures were the incidence and risk factors of VH.

From 2001 to 2010, the database claim 4379 newly diagnosed cases were identified with VH. The average incidence of VH in Taiwan was 4.8 cases per ten-thousand person-years generally and increased with time especially in subjects who aged between 40 and 59y and when the VH was associated with proliferative diabetic retinopathies or retinal vein occlusions. A definitely upward trends in the incidence of VH from 2001 to 2010 were noted (P-value for increasing trend <0.001). Univariate Cox's regression analysis pointed out that older age (for 40-59, P<0.001, HR=9.39; for ≥60, P<0.001, HR=11.39), male gender (P=0.03, HR=1.07) and subjects who had been prescribed anti-coagulation drug included aspirin, warfarin and clopidogrel (P<0.001, HR=2.20) were significant risk factors for suffering from VH.

The incidence of VH is estimated being 4.8 cases per 10 000 person-years in Taiwan. Age, male gender and having been prescribed anti-coagulation drugs are associated with the incidence of VH.