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Abstract

National data from the Asia–Pacific region suggest that stroke accounts for over 10% of female deaths. With general aging in the region, and longer life expectancies for women than men, action is required to maintain recent improvements in female death rates from stroke. However, local data on incidence and risk factors for stroke amongst women are scarce. Data from 214,032 women in the Asia Pacific Cohort Studies Collaboration were thus used to investigate the risk factors for stroke in the region. Raised systolic blood pressure and diabetes were found to be key risk factors for both ischemic (IS) and hemorrhagic (HS) stroke. After adjustment for other risk factors, every extra 10 mmHg systolic blood pressure increased risk of IS by 36% and HS by 69%, whilst diabetes increased risk of IS by 170% and HS by 147%. Smoking was also an important risk factor for IS and HS; risk was reduced by quitting.

Keywords

blood pressure diabetes ischemic stroke hemorrhagic stroke smoking

Although epidemiological data on stroke are voluminous, the majority of published information comes from western countries, with relatively few data, especially age-standardized incidence data, from the Asia–Pacific region [1], where the largest proportion of the world's population resides. Stroke is the second biggest killer worldwide, accounting for approximately 10% of all deaths in 2004, and is the sixth most important contributor to healthy life years lost [101]. In China, it has been estimated that stroke reduces years of future life by 20–40% whilst, following a stroke, active life may be reduced by as much as 90% [2]. Stroke is predominantly a disease of old age, the total population of the Asia–Pacific region is aging, women generally live longer than men and (perhaps consequent to suffering stroke at an older age) short-term survival after stroke is generally worse for women than men [1,3,4]. Hence the issue of stroke amongst women in the Asia–Pacific region is clearly of huge importance in global public health.

Three examples of the impact of stroke for women in the region will serve as an illustration, bearing in mind that age-standardized incidence and mortality rates are essential to reliably compare time trends within and among nations. In Australia, the number of stroke deaths amongst women has been higher than amongst men for at least 30 years (Figure 1) [102], whilst female deaths have outnumbered male deaths in Japan since the early 1980s (Figure 2) [103], and in South Korea since 1992 (Figure 3) [104]. These sex differences are certainly confounded by aging, but the absolute numbers are informative. In all three nations, the number of stroke deaths has decreased in recent years, although the trend is less apparent in Australia, and the decrease in Japan preceded that in South Korea. The proportion of deaths from stroke amongst all deaths in Australian women has stayed fairly static in the last 20 years (Figure 4). In Japanese women, as much as 25% of all deaths were from stroke approximately 40 years ago (Figure 5), but this percentage has now approximately halved. In South Korean women, stroke peaked as a proportion of all deaths in 1994 (18%) and stayed close to this percentage for the next 10 years, before declining back to the levels last seen in the 1980s (Figure 6).

Figure 1.

Fatal strokes amongst women and men in Australia, 1984–2008.

Figure 2.

Fatal strokes amongst women and men in Japan, 1951–2009.

Figure 3.

Fatal strokes amongst women and men in South Korea, 1983–2008.

Figure 4.

Fatal strokes by type as a percentage of all deaths amongst women in Australia, 1998–2008.

Figure 5.

Fatal strokes by type as a percentage of all deaths amongst women in Japan, 1951–2009.

Figure 6.

Fatal strokes by type as a percentage of all deaths amongst women in South Korea, 1983–2008.

Two issues arise when interpreting findings on the epidemiology of stroke from western countries within the context of the Asia–Pacific region. First, in some countries in the Asia–Pacific region coronary heart disease (CHD) is less common than stroke, unlike Western countries [5]. Second, amongst all strokes, hemorrhagic stroke (HS) is more often observed in Asia than in the western world, where ischemic stroke (IS), with a lower case fatality rate, is far more common. Even so, the relative amount of HS is changing with time, probably due to the epidemiological transition to a western lifestyle [5 –7]. Thus, in China, relatively old studies of stroke incidence reported IS percentages of approximately 50%, and HS of 45%, amongst all reported strokes, whereas new studies have found between 44 and 79% for IS and 19–48 for HS [3]. This compares with typical percentages in western countries of 67–81% for IS and 6–20% for HS [8]. HS may well show different associations with risk factors, or even have different risk factors, to IS [9].

Therefore, it is important that stroke subtype is accounted for when assessing risk factors for stroke in the Asia–Pacific region. Unfortunately, this requires expensive investigation, such as CT scans, which may not be available. For example, Figure 4 shows that the majority of female fatal strokes in Australia are of unknown or other (i.e., not IS or HS) subtype [102]. Since these other subtypes are rare, it is clear that stroke subtyping after death is very incomplete in Australia. Japan probably has the most extensive system of stroke verification in the world, with approximately 80% of female fatal strokes subtyped in most years (Figure 5) [103]. South Korea lies in-between (Figure 6). Australia has seen constant proportions of female deaths due to IS since 1998, but a halving of deaths due to HS as a proportion of all deaths (Figure 4) [104]: overall, the percentage of all deaths that are due to stroke has decreased from 12% in 1998 to 10% in 2008. Japan has shown a shrinking of the relative importance of HS as a proportion of all deaths since 1960, with a growth and then a decline in IS over the last 60 years (Figure 5). At present, approximately 11% of all deaths amongst Japanese women are due to stroke, of which approximately two-thirds are ischemic, which contrasts sharply with the 1960s when approximately three-quarters of fatal strokes were hemorrhagic. Although interpretation is hampered by the relatively large number of unknown stroke subtypes, South Korean women appear to have experienced trends similar to those for Japanese women in the absolute and relative percentages of deaths due to IS and HS in the last 20 years, with a time lag (Figure 6). At present, approximately 13% of female South Korean fatalities are caused by stroke, and, of these, more than 60% are ischemic, but before 1994, HS was at least three-times as likely to be the cause of death as IS. The reasons for these differences between countries and over time can be speculated [5], but large, high-quality epidemiological studies are required in order to provide hard evidence. It is most useful if such studies include nonfatal events; owing to the much higher case fatality ratio of HS, mortality data, such as that reported above, can give a misleading impression of the relative frequency of HS. From studies where incidence data are available, IS is generally more common than HS.

This article uses the largest known collaborative study of cardiovascular disease (CVD) and its risk factors, in the Asia–Pacific region, the Asia Pacific Cohort Studies Collaboration (APCSC), to investigate the relationship between putative risk factors and fatal and nonfatal HS and IS.

Methods

Details of the APCSC have been published previously [10]. In brief, studies included had to have a cohort design with selection that was not based upon any disease or risk factor, have baseline information on age, sex and blood pressure, and have cause of death reported during follow-up of at least 5000 person-years. Some cohorts additionally reported nonfatal CVD events. Cohorts suitable for inclusion were classified as from Asia if their participants were recruited from mainland China, Hong Kong, Japan, Singapore, South Korea, Taiwan or Thailand; or ANZ if their participants were recruited from Australia or New Zealand.

The current investigation is restricted to women, but earlier papers from APCSC have reported associations with stroke for men and women combined, often using an earlier (less complete) version of the study database than is employed in this article [11 –20]. A further restriction here is that analyses are only given for those major CVD risk factors for which at least 100 IS and HS events were recorded amongst women: diabetes, smoking, blood pressure (only systolic is included here, for brevity), total cholesterol, triglycerides and BMI.

At baseline, the presence of diabetes was determined on the basis of a reported history of diabetes, or by applying the 1999 WHO diagnostic criteria to blood glucose levels at baseline [21]. In one included study (Singapore National Health Survey), diabetes status was also determined by an oral glucose tolerance test. Cigarette smoking status (i.e., current/former/never smoked) was self-reported. Height and weight were measured, rather than self-reported, and BMI was calculated as weight over the square of height (kg/m²). A minority of studies reported repeat measures of some of the risk factors during follow-up.

Most studies used database linkage to identify deaths, while others also included scheduled follow-up visits or examined hospital records, particularly to identify nonfatal events. Outcomes were classified according to the Ninth Revision of the International Classification of Diseases (ICD-9). The outcomes considered in this analysis were: total stroke (430–438); HS (431.0–432.9); and IS (433.0–434.9).

All data provided to the Secretariat were checked for completeness and consistency and recoded, when necessary, to maximize comparability across cohorts. Summary reports were referred back to principal investigators of each collaborating study for review and confirmation.

Statistical analyses

Analyses were based on individual participant data. Cox proportional hazard models, adjusted for age and stratified by study, were used to derive the hazard ratios (HRs), and corresponding 95% confidence intervals (CIs), for each of the six risk factors, both for HS and IS. CIs were computed using the method of floating absolute risks [22]. Fatal and nonfatal events were pooled in the analyses. Continuous risk factors were clustered into four ordinal groups, such that an equal number of events occurred in each group. After these initial analyses, continuous risk factors were represented as continuous variables where the association appeared to be approximately log-linear for both IS and HS; otherwise relatively high and low values were compared. The associations for continuous variables were adjusted for regression dilution bias using the repeat measures data [22]. To compare effects in Asia and ANZ, and to simultaneously see the effects of risk factors after adjusting for others, multivariable Cox models were fitted to data stratified by subregion (Asia/ANZ) and interaction by subregion was tested by adding a subregion by risk factor interaction term to a Cox model, taking the subregions together, for each risk factor in turn.

Results

Of the 44 studies in the APCSC, all but two included women. The other 42 studies involved 214,032 women, of whom 79% were from Asia (Table 1). The mean age at baseline was 46 years (51 years in ANZ and 45 years in Asia). Over a mean follow-up of 7.2 years, 272 IS and 399 HS fatal events (225 and 345, respectively, in Asia) were recorded. As expected, the fatal CHD/stroke ratio differed widely: from 1.90 in ANZ to 0.29–0.38 in mainland China, Japan and South Korea. In the 19 studies (17 from Asia) that reported nonfatal, as well as fatal, events, 477 nonfatal IS and 161 nonfatal HS events (352 and 130, respectively, from Asia) were observed. As expected, the percentage that was fatal was higher for HS (65%) than IS (27%).

Table 1.

Summary of studies in the Asia–Pacific Cohort Studies Collaboration that included women.

Study name	Country	n	Age (years)		Systolic BP (mmHg)		Cholesterol (mmol/l)		Triglycerides (mmol/l)		BMI (kg/m²)		Smokers (%)	Diabetes (%)	FU (years)
			Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Aito Town	Japan	973	51	9	134	21	4.7	0.9	1.3	0.4	23	3	1.6	1.1	15.2
Akabane	Japan	1023	54	8	124	19	5.1	0.9	1.2	0.7	23	3	1.0	0.9	11.2
Anzhen	China	4617	54	13	128	25	–	–	–	–	24	4	10.3	–	4.2
Anzhen02	China	2120	45	8	119	18	4.7	0.9	1.1	0.7	24	3	0.5	–	2.9
Beijing Aging	China	1058	69	9	143	25	4.6	1.1	1.6	0.8	24	4	14.2	4.5	4.4
Beijing Steelworkers	China	1042	31	7	116	14	–	–	–	–	–	–	–	–	27.7
CISCH	China	1103	42	6	115	16	–	–	–	–	25	4	0.8	2.1	3.3
Civil Service Workers	Japan	3084	47	5	119	17	5.2	0.9	1.1	0.7	22	3	11.2	1.0	6.5
CVDFACTS	Taiwan	3171	46	15	116	20	5.0	1.2	1.1	0.8	23	4	1.5	2.2	6.5
East Beijing	China	580	45	15	125	25	–	–	–	–	24	4	11.0	6.2	14.2
EGAT	Thailand	797	42	5	116	16	5.7	1.1	1.2	0.6	23	3	6.3	1.0	10.4
Fangshan	China	1746	47	10	135	26	4.6	1.0	1.5	1.1	25	4	21.4	–	3.2
Guangzhou Occupational	China	36,368	40	5	110	15	5.2	1.3	1.4	1.1	23	3	1.3	–	7.8
Hisayama	Japan	912	57	12	135	26	4.2	1.0	–	–	22	3	16.6	–	19.2
Hong Kong	Hong Kong	1727	79	7	150	25	5.4	1.0	1.8	1.4	22	4	10.7	9.1	2.3
Huashan	China	972	53	12	125	21	4.7	0.9	1.5	1.0	24	4	3.8	–	2.6
Kinmen	Taiwan	1343	64	10	138	24	–	–	–	–	24	4	4.8	10.1	2.7
KMIC	South Korea	67,928	43	6	116	13	4.9	0.9	–	–	22	3	0.3	–	4.0
Konan	Japan	679	52	16	129	20	5.0	0.9	1.0	0.5	22	3	4.7	2.2	6.3
Miyama	Japan	601	61	10	134	22	5.3	0.8	1.2	0.7	22	3	7.0	3.0	6.3
Ohasama	Japan	1430	59	11	126	17	5.1	0.9	1.5	0.9	24	3	2.3	7.3	4.2
Saitama	Japan	2254	54	11	134	21	5.1	1.0	1.4	0.9	22	3	7.6	1.4	10.3
Seven Cities Cohorts	China	5895	54	12	130	25	5.2	1.5	1.8	1.0	23	4	16.8	1.3	6.0
Shanghai Factory Workers	China	2856	45	6	122	21	4.2	0.9	–	–	–	–	7.0	–	15.3
Shibata	Japan	1355	57	11	129	21	4.8	1.2	–	–	23	3	4.4	0.9	16.3
Shigaraki Town	Japan	2234	57	14	131	20	5.1	0.9	1.4	0.8	23	3	7.9	3.9	3.9
Shirakawa	Japan	2521	48	12	127	22	4.8	1.0	1.3	0.6	22	3	5.4	1.0	16.8
Singapore Heart	Singapore	1139	40	13	122	24	5.9	1.3	1.2	0.8	24	5	3.0	8.3	12.5
Singapore NHS92	Singapore	1712	39	12	116	19	5.3	1.0	1.2	1.0	23	4	3.0	9.6	6.2
Six Cohorts	China	9051	45	7	120	19	4.2	0.9	–	–	21	3	11.6	–	8.4
Tanno/Soubetsu	Japan	1054	51	7	134	21	5.1	0.9	1.2	0.8	24	3	9.9	6.8	15.3
Tianjin	China	4791	55	12	138	29	–	–	–	–	24	4	39.1	–	5.8
Xi'an	China	571	43	5	126	22	4.6	0.9	1.2	0.6	–	–	11.9	–	18.4
Yunnan	China	203	47	5	118	19	4.4	0.9	–	–	24	3	–	0.5	4.4
Asia		168,910	45	10	119	19	4.9	1.0	1.3	0.9	23	3	4.6	3.1	6.4
Australian Longitudinal Study of Aging	Australia	771	77	7	148	22	6.2	1.3	1.7	1.0	26	5	7.7	6.7	5.2
Australian National Heart Foundation	Australia	4726	43	13	123	19	5.5	1.2	1.3	0.8	25	5	21.1	1.5	8.2
Busselton	Australia	4089	44	17	137	27	6.0	1.4	1.3	0.8	24	4	24.0	1.9	25.6
Canberra	Australia	380	77	5	144	19	–	–	–	–	–	–	9.5	6.1	9.4
Fletcher Challenge	New Zealand	2906	47	17	124	20	5.5	1.2	–	–	25	5	18.4	3.0	5.6
Melbourne	Australia	24,334	55	9	136	20	5.6	1.1	–	–	27	5	9.0	3.1	8.6
Newcastle	Australia	2980	51	10	130	21	5.9	1.1	–	–	26	5	18.4	2.3	9.3
Perth	Australia	4936	45	13	127	21	5.8	1.3	1.1	0.8	25	4	21.1	2.1	12.8
Australia and New Zealand		45,122	51	13	133	22	5.6	1.2	1.2	0.8	26	5	14.2	2.8	10.4
Total		214,032	46	11	122	21	5.1	1.1	1.3	0.9	23	4	6.6	2.9	7.2

BP: Blood pressure; CISCH: Capital Iron and Steel Company; EGAT: Electricity-Generating Authority of Thailand; KMIC: Korean Medical Insurance Company; FU: Follow-up (mean); SD: Standard deviation.

After adjustment for age, diabetes was significantly (p < 0.05) associated with IS: the HR (95% CI) was 2.40 (1.54–3.74). The corresponding HR for HS was lower and not significantly different from unity at 1.50 (0.73–3.10). The HRs for current smoking versus never smoked, by contrast, were virtually identical for IS, which was 1.35 (1.15–1.58) and HS, which was 1.36 (1.17–1.59), with ex-smokers having a risk, for each subtype, in-between current and never smokers (Figure 7). Systolic blood pressure (SBP) is a strong predictor of IS and HS, showing a clear log-linear association down to below 120 mm Hg (Figure 8). The regression dilution and age-adjusted HR for a 10 mmHg higher SBP was 1.38 (1.36–1.40) for IS and 1.52 (1.49–1.55) for HS. Total cholesterol was a positive risk factor only for IS (Figure 9): HRs for a 1 mmol/l higher value were 1.20 (1.15–1.26) for IS and 1.00 (0.94–1.06) for HS. Triglycerides had similar associations for each subtype (Figure 10): for a 0.5 mmol/l higher value the HRs were 1.11 (1.07–1.21) for IS and 1.08 (1.04–1.22) for HS. For BMI, there was evidence of a J-shaped relationship, with a nadir in the second quarter, for IS, but a flat relationship for HS (Figure 11).

Figure 7.

Age-adjusted hazard ratios for ischemic and hemorrhagic stroke by smoking status for women.

Figure 8.

Age-adjusted hazard ratios for ischemic and hemorrhagic stroke by systolic blood pressure group for women.

Figure 9.

Age-adjusted hazard ratios for ischemic and hemorrhagic stroke by total cholesterol group for women.

Figure 10.

Age-adjusted hazard ratios for ischemic and hemorrhagic stroke by triglycerides group for women.

Figure 11.

Age-adjusted hazard ratios for ischemic and hemorrhagic stroke by BMI group for women.

Figures 12 & 13 show subregion-specific, multiple adjusted associations for the six risk factors analyzed. The associations with SBP, diabetes and smoking are similar to those found after only age adjustment, suggesting that these risk factors work independently. Thus, SBP, diabetes and (to a lesser extent) smoking all appear to have positive adjusted associations with both IS and HS. After adjustment, cholesterol has a weak (not quite significant) positive relationship to IS, but no clear association with HS; being overweight or obese may increase the risk of IS, but decrease the risk of HS; and triglycerides have no association with either subtype.

Figure 12.

Multiple-adjusted hazard ratios for ischemic stroke by subregion and overall.

Figure 13.

Multiple-adjusted hazard ratios for hemorrhagic stroke by subregion and overall.

The only instance where there was convincing evidence of a real difference between the subregions was for SBP, where the HRs for Asia were significantly higher than for ANZ for both IS and HS. The increase in risk for every additional 10 mmHg was also higher for HS than for IS, most noticeably in Asia (84 vs 44%). For other risk factors, any differences between subregions were explainable by chance except for the triglycerides–IS association, where the point estimate for ANZ was unreliable. There was also a large differential between the sub-regional HRs for HS associated with diabetes, again explained by inaccurate estimation in ANZ, but here the interaction was not quite significant at the 5% level.

Discussion

This study, of more than 200,000 women, has demonstrated that SBP and diabetes are strongly and independently positively associated with both the major subtypes of stroke for women in the Asia–Pacific region. Smoking is the third risk factor of key importance, and, importantly, these analyses provide evidence of a benefit of quitting for women. Overweight/obesity may also be an important predictor of IS, but may have a negative effect on HS. The evidence for any independent positive effect of cholesterol on IS amongst women was weak, whilst there was no evidence of any effect on HS. No evidence was found for any effect of triglycerides on stroke after accounting for other risk factors, in contrast to a recent study of IS in Denmark [23]. Furthermore, there was no firm evidence of differences in effects of risk factors in Asia or ANZ, with the exception of SBP where effects were qualitatively similar, but differed in magnitude such that the associations were sharper in Asia.

Awareness and control of salt in the diet and use of medication to reduce blood pressure has undoubtedly improved in Asia in recent years; for example, Japan has seen reductions in average salt intake in most recent years [24]. This is likely to explain a great deal of the overall reduction in stroke fatalities in several Asian countries [5,6]. The stronger association of SBP with HS than with IS, seen in Figures 8, 12 & 13, may partially explain the relative decrease in HS deaths in recent years. Australia is yet to experience an intensive national campaign to reduce salt, although an advocacy group is working to change this [105]. Improved tobacco control in the region has undoubtedly had a huge impact in reducing stroke rates, but the data in Figures 7, 12 & 13 suggest that changes in smoking rates will have had relatively little effect on the IS/HS ratio.

Transitions in dietary habits may have had the biggest impact on the IS/HS ratio [5], since increased cholesterol and adiposity may have opposing effects, according to Figures 12 & 13. This hypothesis is supported by other data that show CHD to be increasing, relative to stroke, in Japan [6]. However, the influence of cholesterol on stroke seems to be weak, given that the largest studies, to date, have shown conflicting results. APCSC, taking men and women combined, found a marginally nonsignificant multiple-adjusted positive effect of TC on IS, and a significant negative effect on HS [18]. The Prospective Studies Collaboration found significant effects for TC on IS only amongst 40–59-year-olds, where there was a positive effect; and on HS only amongst 70–79-year-olds, where there was a negative effect [25]. INTERSTROKE [26] found nonsignificant negative associations with both subtypes, although this result must be viewed with caution owing to the weak study design utilized. A large collaborative study in Japan also found no association of TC with any stroke subtype [27].

Diabetes, which is strongly associated with increased body fat, is on the rise throughout the Asia–Pacific region [28]. In this study, diabetes was found to be positively associated with IS after age and multiple adjustment, both in Asia and ANZ. For HS, the evidence was more mixed, but the most compelling analysis, multivariable adjustment using all the data (Figure 13), found a statistically significant excess risk for HS of a similar magnitude to IS (Figure 12). Thus, diabetes is unlikely to have had a role in the recent declines of either deaths due to stroke or the IS/HS ratio amongst women. Rather, it may have an important role in increasing stroke in the future.

This study has the advantage of a large sample size, but the disadvantages of lacking both a common protocol across the studies and an objective measure of tobacco inhalation within studies. Whilst stroke was analyzed according to its two major subtypes, HS and IS, etiological differences may occur between subtypes of finer division. For example, a Japanese study has reported low-density lipoprotein cholesterol to be a risk factor for atherothrombotic infarction, but not other types of IS [29]. Furthermore, many cases of stroke in this study were not even able to be classified to one of the two major subtypes.

Future perspective

The implications of the findings presented here are mixed. First, there is clearly a continuing decline in stroke deaths amongst women in the Asia–Pacific region, which suggests that public health and clinical initiatives are already leading to long-term improvements. As well as wholesale changes in stroke deaths for the better, decreases in the relative proportion of deaths due to the hemorrhagic subtype, with its worse prognosis, also point to improvements, although the consequences of a nonfatal stroke are often far from trivial. Data on stroke incidence are rare in the region, and there is a clear need for national registries of stroke, as well as CHD.

The risk factors for stroke of both main subtypes are frequently associated with lifestyle choices, most obviously for smoking. Thankfully, smoking in women is still unusual in most Asian countries, although the prevalence of smoking is on a par with men in Australia and New Zealand [30]. The problem here is that smoking may be portrayed as sexy and empowering to young women, thus requiring sustained vigilance through tobacco control programs. Women are, in many cases in the Asia–Pacific region, primarily responsible for family food choices, storage and preparation. The education of women regarding the risks of excess salt may be the public health strategy with the biggest bang for the buck. Finally, the inexorable rise in diabetes within the Asia–Pacific region is of great concern, with reported national adult rates already as high as 15% [31]. Diabetes is a stronger risk factor for IS amongst women than men [32], and results here suggest it is also an important risk factor for HS amongst women. Hence, actions to control the diabetes epidemic, and to prevent its sequelae, should be expected to have a huge impact on death and disability amongst women from the Asia–Pacific region.

Executive summary

Regional perspectives on stroke

Stroke accounts for more than 10% of fatalities amongst women in the Asia–Pacific region.

In recent years, stroke deaths in the region have been decreasing and the relative number of deaths from hemorrhagic stroke has decreased, relative to ischemic stroke.

Risk factors for stroke in the Asia–Pacific region

Data from women in the Asia–Pacific Cohort Studies Collaboration show that systolic blood pressure and diabetes are the most important risk factors for stroke of both subtypes. Smoking is also a key risk factor, with reduced risk for those who have quit.

Raised BMI is associated with a higher risk of ischemic stroke, but not hemorrhagic stroke.

Actions required

National stroke registries are needed to monitor incidence and mortality.

Education regarding the dangers from salt used in food preparation and storage can be expected to have a huge impact on reducing stroke rates, especially if backed by government policies.

Tobacco control initiatives, targeted to women's issues, should also help to reduce the risk of stroke amongst women.

Footnotes

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Appendix

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The Epidemiology of Stroke Amongst Women in the Asia–Pacific Region

Abstract

Keywords

Methods

Statistical analyses

Results

Discussion

Future perspective

Footnotes

Appendix

References