1432 Original Article Page 1 of 11 Temporal, geographical and demographic trends of stroke prevalence in China: a systematic review and meta-analysis Jinli Liu1, Zumin Shi2, Ruhai Bai1, Jinge Zheng1, Shuang Ma1, Junxiang Wei1, Guangzhi Liu3, Youfa Wang1,4 1School of Public Health, Global Health Institute, Xi’an Jiaotong University Health Science Center, Xi’an, China; 2Human Nutrition Department, College of Health Sciences, QU Health, Qatar University, Doha, Qatar; 3Department of Neurology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China; 4Fisher Institute of Health and Well-Being, Department of Nutrition and Health Sciences, College of Health, Ball State University, Muncie, Indiana, USA Contributions: (I) Conception and design: Y Wang, Z Shi, J Liu; (II) Administrative support: Y Wang; (III) Provision of study materials or patients: R Bai, J Liu; (IV) Collection and assembly of data: J Liu, J Zheng, S Ma; (V) Data analysis and interpretation: Z Shi, Y Wang, J Liu; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors. Correspondence to: Youfa Wang, MD, PhD, MS, Professor & Dean. Global Health Institute, School of Public Health, Xi’an Jiaotong University Health Science Center, Xi’an, China. Email: [email protected]. Background: China has made large efforts to reduce stroke prevalence. We aimed to systematically examine the prevalence of stroke in China over the past two decades. Methods: Databases, including China National Knowledge Infrastructure, Wanfang, VIP, and PubMed, were systematically searched for studies published in English or Chinese that reported stroke prevalence in China during 2000–2017. Meta-analysis was conducted to estimate the pooled stroke prevalence and the variations in stroke prevalence subgroups stratified by age, gender, time period, and region. Results: In total, 96 papers met the inclusion criteria. Meta-analysis showed that the overall estimated national prevalence was 5.1% (5.0–5.3%) with large variations across regions: 3.1% (2.5–3.6%) in south China, 3.4% (3.0–3.8%) in southwest China, 3.6% (3.3–3.8%) in east China, 5.0% (4.7–5.4%) in central China, 5.8% (4.6–7.1%) in northwest China, 6.0% (5.0–7.0%) in northeast China, and 8.0% (7.4–8.5%) in north China. Men had a higher prevalence than women [7.3% (6.9–7.7%) vs. 5.6% (5.2–6.0%)]. Stroke prevalence increased with age, was 1.2% (1.0–1.3%), 2.9% (2.6–3.2%), 5.9% (5.2–6.5%), and 8.7% (8.0– 9.5%) in the 40–49, 50–59, 60–69, and ≥70 years old groups, respectively. Conclusions: Men, people being older, or living in northern China had higher stroke prevalence. More vigorous efforts are needed in China to prevent stroke. Keywords: Stroke; trends; meta-analysis; China Submitted Dec 13, 2019. Accepted for publication Jul 27, 2020. doi: 10.21037/atm-19-4342 View this article at: http://dx.doi.org/10.21037/atm-19-4342 Introduction and population aging, especially in low- and middle-income countries (4). Stroke also creates tremendous economic Stroke is the second leading cause of death worldwide and pressure on health care systems (5,6). The annual incidence in China, where a fifth of the world’s population resides. of stroke is expected to increase to over 23 million and With over 2 million new cases annually, stroke is associated annual deaths to 7.8 million by 2030 in the absence of with the highest disability-adjusted life-years lost among all effective global public health responses (7,8). chronic diseases in China (1-3). The burden of stroke has In China, about 2.4 million people have a new onset increased worldwide because of shifts in people’s lifestyles of stroke each year. About 75% of individuals living with © Annals of Translational Medicine. All rights reserved. Ann Transl Med 2020;8(21):1432 | http://dx.doi.org/10.21037/atm-19-4342 Page 2 of 11 Liu et al. Prevalence of stroke in China over the past 20 years stroke will develop neurological sequela that leads to various was aged 40 and over; (III) participants were selected from degrees of disability (9,10). Stroke also brings a heavy the general population or those who undertook routine financial burden to the affected families and society. Over physical examinations organized by employers; (IV) the the past decade, China has implemented several national main outcome was the prevalence of stroke; (V) a cross- and regional programs for stroke prevention and control. sectional study or large cohort study for monitoring These included the well-known Healthy China 2020 and purposes; (VI) sample size >1,000; and (VII) age-specific Healthy China 2030 programs that were launched in 2012 data were presented. and 2016, respectively. Regional reports show the beneficial Studies were excluded when meeting the following effects of these programs, with a risk of stroke in high-risk criteria: (I) no age-specific data were provided and a single individuals and the general population possibly benefitting age group over 30 years; (II) the number of participants more than others from such programs (11). A systematic was not provided or the confidence interval could not be examination of the trends of stroke prevalence in China will estimated; (III) the papers were published repeatedly; or enable us to gain important insights into the effectiveness of (IV) participants were hospitalized patients or patients with these intervention programs. certain diseases or other special groups (such as pregnant This study aimed to systematically examine the temporal females, nursing mothers, smoking, drinking, military changes in the prevalence of stroke and also differences in police, athletes, and those on weight loss or diet programs). the prevalence stratified by age, gender, and region over Our initial screening resulted in 3,016, 3,033, 2,272, the past two decades in China. This information will aid and 1,577 articles from the CNKI, Wanfang, VIP, and intervention efforts in future. We present the following PubMed databases, respectively. Ninety-six studies met article in accordance with the PRISMA reporting checklist the inclusion criteria (Figure 1). Two authors separately (available at http://dx.doi.org/10.21037/atm-19-4342) (12). reviewed the studies. When there were differences between their assessments, a third author provided an additional assessment. Methods Literature search Data extraction We searched the following databases: (I) the China National We extracted prevalence data of cross-sectional studies Knowledge Infrastructure (CNKI) (http://www.cnki.net/); (II) and cohort studies in the general population using a Wanfang Database (http://www.wanfangdata.com.cn/index. standardized data-collection form that included the html); (III) China Science and Technology Journal Database following information: authors, publication year, study (VIP) Database (http://www.cqvip.com/); and (IV) PubMed design, study aim/objective, study period, region, sample (https://www.ncbi.nlm.nih.gov/pmc/). We searched for sizes, stroke prevalence (%) and 95% confidence interval studies published between January 1, 2000, and December (CI). Seven geographic regions in China were defined as 31, 2017, using the search terms “stroke” OR “transient north (Beijing, Tianjin, Hebei, Shanxi, and Inner Mongolia); ischemic attack” OR “intracerebral hemorrhage” OR “isch(a) northeast (Liaoning, Jilin, and Heilongjiang); northwest emic stroke” OR” intraparenchymal” OR “subarachnoid” (Ningxia, Xinjiang, Qinghai, Shaanxi, and Gansu); central OR “h(a)emorrhage” AND “Chinese” OR “China” AND (Hubei, Hunan, and Henan); east (Shandong, Jiangsu, “prevalence” OR “epidemic.” We also reviewed the reference Anhui, Zhejiang, Fujian, Jiangxi, and Shanghai); southwest lists of the retrieved publications to identify any additional (Sichuan, Yunnan, Guizhou, Tibet, and Chongqing); south relevant studies. Our meta-analysis was conducted according (Guangdong, Guangxi, and Hainan); special administrative to the preferred reporting items of the Meta-Analysis of region (Hong Kong and Macau); and Taiwan. Observational Studies in Epidemiology (MOOSE) statement for meta-analyses of observational studies (13). Quality of literature evaluation For evaluation of the included studies, we used the Study selection literature quality assessment criteria proposed by Suriah Studies were included if they met the following criteria: (I) AR, Chong TJ and Yeoh BY (Table S1) (14). Based on the study population was Chinese; (II) the study population these quality assessment criteria, studies were scored © Annals of Translational Medicine. All rights reserved. Ann Transl Med 2020;8(21):1432 | http://dx.doi.org/10.21037/atm-19-4342 Annals of Translational Medicine, Vol 8, No 21 November 2020 Page 3 of 11 Total articles identified (N=9,898) CNKI (N=3,016) Wanfang (N=3,033) VIP (N=2,272) PubMed (N=1,577) Duplicates (N=1,206) Titles and abstracts for the primary screening (N=8,692) Removed unrelated literature (n=8,226): Cell experiments (n=563); Animal experiments (n=1,239); lntervention studies (n=1,975); Study of population under 18 years (n=783); Clinical studies in hospital patients and special groups (n=2,982); Sample size less than 1,000 (n=684) Full text articles to screen (N=466) Excluded =370: The single age grouping was over 30 years(N=21); Survey time was not in 1998–2017 and published time was not in 2000 to 2017 (N=43); Review article (N=42); Literatures could not be standardized (N=264) 96 studies included Figure 1 Flowchart of systematic review procedure to select the 96 studies included. from 1 to 5 (highest to lowest quality score, respectively). specified number of sampling units (e.g., two towns, three A score of 1= nationally representative studies with clinics); a score of 4= included large sample sizes (>1,000 large sample sizes and that employed random selection persons) even though the samples were not randomly techniques; a score of 2= large, randomly selected selected; and a score of 5= small, non-randomly selected samples from an entire state in the country; a score samples (14).