Population-Based Incidence Rates of First-Ever Stroke in Central Vietnam.

Hirotomo Yamanashi,Nguyen Thi Hien Anh,Le Huu Tho,Koya Ariyoshi,Dang Duc Anh,Tran Van Huy,Mai Quang Ngoc,Lay-Myint Yoshida,Akira Tsujino,Kensuke Takahashi,Sharon E Cox,Sharon E Cox,Takahiro Maeda,Vu Dinh Thiem,Motoi Suzuki,Michiko Toizumi

doi:10.1371/journal.pone.0160665

Abstract

IntroductionStroke incidence data with methodologically acceptable design in Southeast Asia countries is limited. This study aimed to determine incidence of age-, sex- and subtype-specific first-ever stroke (FES) in Vietnam.MethodsWe conducted a hospital-based retrospective study, targeting all stroke cases hospitalized at a solo-provider hospital in our study site of Nha Trang from January 2009 to December 2011 with International Classification of Diseases, 10th revision (ICD-10) codes I60-69. We calculated positive predictive values (PPVs) of each ICD-10-coded stroke by conducting a detailed case review of 190 randomly selected admissions with ICD-10 codes of I60-I69. These PPVs were then used to estimate annual incident stroke cases from the computerized database. National census data in 2009 was used as a denominator.Results2,693 eligible admissions were recorded during the study period. The crude annual incidence rate of total FES was 90.2 per 100,000 population (95% CI 81.1–100.2). The age-adjusted incidence of FES was 115.7 (95% CI 95.9–139.1) when adjusted to the WHO world populations. Importantly, age-adjusted intracerebral hemorrhage was as much as one third of total FES: 36.9 (95% CI 26.1–51.0).ConclusionsWe found a considerable proportion of FES in Vietnam to be attributable to intracerebral hemorrhage, which is as high or exceeding levels seen in high-income countries. A high prevalence of improperly treated hypertension in Vietnam may underlie the high prevalence of intracerebral hemorrhagic stroke in this population.

Highlights

Stroke incidence data with methodologically acceptable design in Southeast Asia countries is limited
We found a considerable proportion of firstever stroke (FES) in Vietnam to be attributable to intracerebral hemorrhage, which is as high or exceeding levels seen in high-income countries
The recent studies in low- and middleincome countries (LMICs) showed relatively higher ageadjusted first-ever stroke (FES) incidence per 100,000 person-years compared to high-income countries; 108.2 in Chile, 116.1 in Georgia, 137 in Brazil, and 135 in India in LMICs versus 97 in Italy, 102.8 in Barbados, 73 in UK, 102.9 in New Zealand [5,6,7,8,9,10,11,12,13]

Summary

Introduction

Stroke incidence data with methodologically acceptable design in Southeast Asia countries is limited. Published stroke incidence data with methodologically reliable design is limited in LMICs. The recent studies in LMICs showed relatively higher ageadjusted first-ever stroke (FES) incidence per 100,000 person-years compared to high-income countries; 108.2 in Chile, 116.1 in Georgia, 137 in Brazil, and 135 in India in LMICs versus 97 in Italy, 102.8 in Barbados, 73 in UK, 102.9 in New Zealand [5,6,7,8,9,10,11,12,13]. This study had several limitations: a) no center included participants over 75 years old; b) it was not designed to investigate incidence by different pathological types; and c) it was not prospective in design. Because standard definition of stroke requires imaging test such as brain CT scan or MRI, which are not readily available in LMICs, information of pathological type-specific stroke incidence has mostly been confined to high-income countries [17]

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