Urbanization and stroke prevalence in Taiwan: analysis of a nationwide survey

Primary Sjögren's Syndrome and the Risk of Acute Myocardial Infarction: A Nationwide Study

BACKGROUND

Patients with autoimmune diseases have a high cardiovascular risk. However, few data are available on the risk of acute myocardial infarction (AMI) in patients diagnosed with primary Sjögren's syndrome (PSS). We conducted a large nationwide cohort study to investigate the possible association between PSS and the risk of AMI.

METHODS

Between the years 2000-2006, a total of 5205 patients with newly diagnosed PSS and no history of AMI were identified from the Registry of Catastrophic Illness, a sub-dataset of the National Health Insurance Research Database in Taiwan. The control group, which consisted of subjects without systemic autoimmune disease or previous AMI, was matched by the date of enrollment, age, gender, history of coronary artery disease, diabetes, hypertension, chronic kidney disease, and hyperlipidemia. The study endpoints were the occurrence of AMI.

RESULTS

Of the 5205 subjects with PSS and 5205 controls included in the study, 77 (35 PSS patients and 42 controls) developed AMI during the mean 3.7-year (interquartile range, 2.1-5.1 years) follow-up period. The incidence of AMI was similar in PSS patients and controls (1.91/1000 versus 2.25/1000 person-years). Multivariate analysis adjusted for baseline covariates demonstrated an insignificant association between PSS and AMI [adjusted hazard ratio, 0.86; 95% confidence interval (CI), 0.55-1.35; p = 0.506], suggesting that PSS does not increase the risk of AMI.

CONCLUSIONS

PSS is not associated with a higher risk of subsequent AMI.

KEY WORDS

Acute myocardial infarction; Atherosclerosis; Primary Sjögren's syndrome.

Association of stroke with the receptor-binding profiles of antipsychotics-a case-crossover study

BACKGROUND

Previous research suggests a link between antipsychotic use and stroke, but the relationships between receptor-binding profiles of antipsychotics and the risk of cerebrovascular events are unclear.

METHODS

A total of 14,584 patients with incident stroke were enrolled in the National Health Insurance Research Database in Taiwan from 1998 to 2007. We conducted a case-crossover study to compare the rates of antipsychotic use. The effects of receptor-binding profiles of antipsychotics on stroke risk were estimated, while the moderating effects of age, sex, presence of dementia, and duration of antipsychotic treatment were evaluated by stratified analyses.

RESULTS

The adjusted odds ratio of stroke risk with antipsychotics exposure was 1.60 (95% confidence interval, 1.51-1.69) using a 14-day time window. The use of antipsychotics with a high binding affinity of M1 muscarinic and α2 adrenergic receptors was associated with a greater risk of stroke than the use of other types of antipsychotics. An increased risk of stroke with antipsychotic use was noted in the patients who were older and/or who suffered from dementia. Moreover, our results showed that stroke risk with antipsychotic use was in a dose-related relationship.

CONCLUSIONS

Our findings suggest an association between stroke risk and high M1 muscarinic and α2 adrenergic affinity. The clinical implication is to start antipsychotics treatment at low dosages and to closely monitor the side effects in the initial treatment, particularly for individuals with older age and the presence of dementia.

Hip fracture and risk of acute myocardial infarction: a nationwide study

Osteoporotic fractures are associated with increased mortality risk. However, little data are available on the risk of acute myocardial infarction (AMI) after hip fracture. Therefore, we investigated whether hip fracture increased the risk of AMI in a large, nationwide cohort study. We obtained data from 8758 patients diagnosed with hip fracture from 2000 to 2009 and from 4 matched controls for each patient from the Longitudinal Health Insurance Database (LHID 2000), Taiwan. Controls were matched for age, sex, comorbid disorders, and enrollment date. All subjects were followed up from the date of enrollment until AMI, death, or the end of data collection (2009). Cox's regression model adjusted for age, sex, comorbid disorders, and medication was used to assess independent factors determining the risk of development of AMI. As expected, despite the matching, the hip fracture patients had more risk factors for AMI at baseline. A total of 8758 subjects with hip fractures and 35,032 controls were identified. Among these patients, 1183 (257 hip fracture patients and 926 controls) developed AMI during the median 3.2-year (interquartile range 1.4 to 5.8 years) follow-up period. Patients with hip fractures had a higher incidence of AMI occurrence when compared with controls (8.7/1000 person-years versus 6.82/1000 person-years). Multivariate analysis adjusted for baseline covariates indicated that hip fracture was associated with a greater risk for AMI development (hazard ratio [HR] = 1.29; 95% confidence interval [CI] 1.12-1.48; p < 0.001). We conclude that hip fracture is independently associated with a higher risk of subsequent AMI.

Does adhesive capsulitis of the shoulder increase the risk of stroke? A population-based propensity score-matched follow-up study

OBJECTIVES

A previous population-based study reported an increased risk of stroke after the occurrence of adhesive capsulitis of the shoulder (ACS), but there were substantial imbalances in the distribution of age and pre-existing vascular risk factors between subjects with ACS and without ACS, which might lead to a confounded association between ACS and stroke. The purpose of the present large-scale propensity score-matched population-based follow-up study was to clarify whether there is an increased stroke risk after ACS.

METHODS

We used a logistic regression model that includes age, sex, pre-existing comorbidities and socioeconomic status as covariates to compute the propensity score. A total of 22025 subjects with at least two ambulatory visits with the principal diagnosis of ACS in 2001 was enrolled in the ACS group. The non-ACS group consisted of 22025, propensity score-matched subjects without ACS. The stroke-free survival curves for these 2 groups were compared using the Kaplan-Meier method. Stratified Cox proportional hazard regression with patients matched on propensity score was used to estimate the effect of ACS on the occurrence of stroke.

RESULTS

During the two-year follow-up period, 657 subjects in the ACS group (2.98%) and 687 in the non-ACS group (3.12%) developed stroke. The hazard ratio (HR) of stroke for the ACS group was 0.93 compared to the non-ACS group (95% confidence interval [CI], 0.83-1.04, P = 0.1778). There was no statistically significant difference in stroke subtype distribution between the two groups (P = 0.2114).

CONCLUSIONS

These findings indicate that ACS itself is not associated with an increased risk of subsequent stroke.

Characteristics of comorbidities and costs among patients who died from systemic lupus erythematosus in Taiwan

INTRODUCTION

Systemic lupus erythematosus (SLE) is prevalent among young female adults, particularly in Asia. In Taiwan, features of end-of-life SLE patients remain unclear.

MATERIAL AND METHODS

Data regarding SLE patients whose hospitalization ended up with death were collected and analyzed from the repository of the National Health Insurance Research Database, Taiwan, from 2005 to 2007.

RESULTS

A total of 302 subjects were enrolled and the majority of these were young to middle-aged women (45.8 ±18.5 years); only one third of them were treated by rheumatologists. Eight patients (2.6%) with comorbid cancers received hospice care. Sepsis/bacteremia (42.1%) was the major acute comorbidity. Nephropathy/nephritis (35.1%) represented the major chronic comorbidity. Among 27 subjects with comorbid cancers, gynecological cancers were the most common (18%). Among the inpatient costs, the cost of prescriptions accounted for the majority (21.7 ±11.5%). Under a multivariate logistic regression, advanced age (≥ 65 years) correlated positively with acute lower respiratory conditions (ALRC) and diabetes mellitus (DM), and male gender correlated negatively with nephropathy/nephritis. The nephropathy/nephritis correlated positively with hospital stays > 14 days. The ALRC was closely associated with acute respiratory failure, but not with shock. However, shock was closely associated with hospital stays ≥ 14 days and sepsis/bacteremia. Cancer development was inversely correlated to nephropathy/nephritis, acute respiratory failure, and shock (all p < 0.05).

CONCLUSIONS

The end-of-life SLE patients revealed aforementioned characteristics and relationships. Sepsis/bacteremia, acute respiratory failure, and ALRC contributed most frequently to the ultimate death of acutely ill SLE patients.

Stock or stroke? Stock market movement and stroke incidence in Taiwan

This paper investigates the impact of stock market movement on incidences of stroke utilizing population-based aggregate data in Taiwan. Using the daily data from the Taiwan Stock Exchange Capitalization Weighted Stock Index and from the National Health Insurance Research Database during 2001/1/1–2007/12/31, which consist of 2556 observations, we examine the effects of stock market on stroke incidence – the level effect and the daily change effects. In general, we find that both a low stock index level and a daily fall in the stock index are associated with greater incidences of stroke. We further partition the data on sex and age. The level effect is found to be significant for either gender, in the 45–64 and 65≥ age groups. In addition, two daily change effects are found to be significant for males and the elderly. Although stockholdings can increase wealth, they can also increase stroke incidence, thereby representing a cost to health.

The incidence of venous thromboembolism in cervical cancer: a nationwide population-based study

Background

Venous thromboembolism (VTE) is a life-threatening condition that occurs as a complication of cervical cancer. The aim of this study was to evaluate the incidence of VTE in cervical cancer patients during a 5-year follow-up.

Methods

The study analyzed data deposited between 2003 and 2008 in the National Health Insurance Research Database (NHIRD), provided by the National Health Research Institutes in Taiwan. Totally, 1013 cervical cancer patients after treatment and 2026 appendectomy patients were eligible. The Kaplan-Meier method and the Cox proportional hazards model were used to assess the VTE risk.

Results

The 5-year cumulative risk for VTE was significantly higher in the cervical cancer group than in the control group (3.3% vs 0.3%, p < 0.001). The hazard ratio for VTE was 10.14 times higher in the cervical cancer group than in the controls. The combined presence of more comorbidities was associated with a higher risk for VTE. Furthermore, cervical cancer patients without VTE had a significantly higher survival (75.3% vs 30.3%, p < 0.001).

Conclusions

The cumulative risk of VTE was significantly higher in cervical cancer patients, and these patients also had lower survival rates. Strategies to reduce these risks need to be examined.

The incidence and relative risk of stroke in patients with schizophrenia: a five-year follow-up study

OBJECTIVE

This study aimed to estimate the incidence and relative risk of stroke and post-stroke all-cause mortality in patients with schizophrenia.

METHODS

This study identified a study population from the National Health Insurance Research Database (NHIRD) between 1999 and 2003 that included 80,569 patients with schizophrenia and 241,707 age- and sex-matched control participants without schizophrenia. The participants were randomly selected from the 23,981,020-participant NHIRD, which consists of 96% Taiwanese participants. Participants who had experienced a stroke between 1999 and 2003 were excluded. Using data from the NHIRD between 2004 and 2008, the incidence of stroke (ICD-9-CM code 430-438) and patient survival after stroke were calculated for both groups. After adjusting for confounding risk factors, a Cox proportional-hazards model was used to compare the five-year stroke-free survival rate to the all-cause mortality rate across the two cohorts.

RESULTS

Over five years, 1380 (1.71%) patients with schizophrenia and 2954 (1.22%) controls suffered from strokes. After adjusting for demographic characteristics and comorbid medical conditions, patients with schizophrenia were 1.13 times more likely to have a stroke (95% CI=1.05-1.22; P=0.0006). In addition, 1039 (24%) patients who had a stroke died during the follow-up period. After adjusting for patient, physician and hospital variables, the all-cause mortality hazard ratio for patients with schizophrenia was 1.23 (95% CI=1.06-1.41; P=0.0052).

CONCLUSIONS

During a five-year follow-up, the likelihood of developing a stroke and the all-cause mortality rate were greater among patients with schizophrenia as compared with the control group.

Chronic kidney disease itself is a causal risk factor for stroke beyond traditional cardiovascular risk factors: a nationwide cohort study in Taiwan

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of mortality and morbidity in patients with chronic kidney disease (CKD). In Taiwan, CVD is dominated by strokes but there is no robust evidence for a causal relationship between CKD and stroke. This study aimed to explore such causal association.

METHODS

We conducted a nationwide retrospective cohort study based on the Taiwan National Health Insurance Research Database from 2004 to 2007. Each patient identified was individually tracked for a full three years from the index admission to identify those in whom any type of stroke developed. The study cohort consisted of patients hospitalized with a principal diagnosis of CKD and no traditional cardiovascular risk factors at baseline (n = 1393) and an age-matched control cohort of patients hospitalized for appendectomies (n = 1393, a surrogate for the general population). Cox proportional hazard regression and propensity score model were used to compare the three-year stroke-free survival rate of the two cohorts after adjustment for possible confounding factors.

RESULTS

There were 256 stroke patients, 156 (11.2%) in the study cohort and 100 (7.2%) in the control cohort. After adjusting for covariates, patients with primary CKD had a 1.94-fold greater risk for stroke (95% CI, 1.45-2.60; p<0.001) based on Cox regression and a 1.68-fold greater risk for stroke (95% CI, 1.25-2.25; p = 0.001) based on propensity score. This was still the case for two cohorts younger than 75 years old and without traditional cardiovascular risk factors.

CONCLUSIONS

This study of Taiwanese patients indicates that CKD itself is a causal risk factor for stroke beyond the traditional cardiovascular risk factors. Primary CKD patients have higher risk for stroke than the general population and all CKD patients, irrespective of the presence or severity of traditional cardiovascular risk factors, should be made aware of the stroke risk and monitored for stroke prevention.

Stroke in South Asia: a systematic review of epidemiologic literature from 1980 to 2010

BACKGROUND

Globally 15 million people have an acute stroke every year and one third of them die secondary to stroke events. Most research on stroke prevention and treatment is done in developed countries, yet more than 85% of strokes occur in developing countries. In particular, stroke remains an underrecognized cause of death and disability in South Asia.

METHODS

We conducted a systematic review to identify reliable and comparable epidemiological evidence on stroke in South Asia from 1980 to 2010. Publications were screened for eligibility to identify only population-based stroke studies.

RESULTS

Of the 71 studies retrieved, only 6 studies from South Asia gave us acceptable estimates of the burden of stroke. Population-based studies from South Asia have stroke prevalence in the range of 45-471 per 100,000. The age-adjusted incidence rate varied from approximately 145 per 100,000 to 262 per 100,000. Rural parts of South Asia have a lower stroke prevalence compared with urban areas.

CONCLUSIONS

Our review highlights the paucity of research data in South Asia. This must be addressed in order to accurately determine the burden of stroke in South Asia, so that specific policy recommendations can be formulated to combat the stroke epidemic in this region.

Increased risk of diabetes in patients with urinary calculi: a 5-year followup study

PURPOSE

No prospective followup study to date to our knowledge has evaluated the relationship between stone disease and the subsequent risk of diabetes mellitus. In this population based study we examine the relationship between a history of urinary calculi and the risk of diabetes mellitus in Taiwan.

MATERIALS AND METHODS

A total of 23,569 adult patients with new diagnoses of urinary calculi from 2001 to 2003 were recruited together with 70,707 matched enrollees as a comparison cohort. All patients were tracked for a 5-year period from the index health care encounter to identify those who had a subsequent diagnosis of diabetes mellitus. Cox proportional hazards models were used to compute the risk of diabetes mellitus for the study and comparison cohorts.

RESULTS

Of a total of 94,276 patients 2,921 (12.39%) from the urinary calculi group and 6,171 (8.73%) from the comparison group received a subsequent diagnosis of diabetes mellitus during the followup period. The stratified Cox proportional analysis showed that, after censoring individuals who died during followup, and adjusting for patient monthly income, geographic location, urbanization level, hypertension, hyperlipidemia and obesity, the hazard of receiving a first diagnosis of diabetes during the 5-year followup was 1.32 times greater for patients with urinary calculi than for those in the comparison cohort (95% CI 1.26-1.39, p <0.001).

CONCLUSIONS

Our results suggest that patients who receive a diagnosis of urinary calculi are at increased risk for diabetes mellitus at 5-year followup.

Urbanization and the utilization of outpatient services under National Health Insurance in Taiwan

OBJECTIVES

This study aims to investigate the relationship between the level of urbanization and the utilization of outpatient services under the National Health Insurance (NHI) program in Taiwan.

METHODS

We adopted a two-part model using data from the 2001 National Health Interview Survey (NHIS) and the 2001 National Health Insurance Research Database (NHIRD) in Taiwan. Data for a total of 20,640 individuals were obtained for subsequent analysis in this study.

RESULTS

The results of the first part, the contact analysis, indicate that individuals residing in areas with lower urbanization levels are less likely to use outpatient services compared to those residing in areas with the highest urbanization levels. The second part of the frequency analysis revealed that, for those individuals that had previously utilized outpatient services, those residing in areas with lower urbanization levels tended to utilize outpatient services less than individuals residing in areas with higher levels of urbanization.

CONCLUSIONS

Our empirical results show that differences between urbanization levels are a major contributory factor associated with the probability and frequency of outpatient utilization in Taiwan.

Increased risk of stroke in young head and neck cancer patients treated with radiotherapy or chemotherapy

BACKGROUND

Chemo-radiotherapy-induced carotid stenosis and cerebrovascular events in head and neck cancer patients can cause severe disability and death. We aimed to estimate the risk of stroke in such patients over a six-year follow-up period.

PATIENTS AND METHODS

The study cohort consisted of head and neck cancer patients (n=10,172). Cox proportional hazard model was used to compare the stroke-free survival rate between the patients treated with radiotherapy or chemotherapy, surgery alone, and surgery with adjuvant therapy after adjusting for possible confounding factors.

RESULTS

At the end of follow-up, 384 patients had strokes: 126 (4.3%) from the surgery alone group, 167 (3.8%) from the radiotherapy or chemotherapy group, and 91 (3.2%) from the surgery with adjuvant therapy (P=0.222). Head and neck cancer patients aged less than 55 years treated with radiotherapy or chemotherapy conferred a 1.8-fold higher risk for stroke (95% CI, 1.22-2.56; P=0.003) after adjusting for patient characteristics, co-morbidities, geographic region, urbanization level, and socio-economic status. There was no statistical difference in stroke risk between different treatment modalities in head and neck cancer patients aged 55 years and more.

CONCLUSIONS

Young head and neck cancer patients treated with radiotherapy or chemotherapy have higher risks for stroke. Different treatment strategies should be considered in such patients.

Increased risk of ischemic stroke in young nasopharyngeal carcinoma patients

PURPOSE

Radiation/chemoradiotherapy-induced carotid stenosis and cerebrovascular events in patients with nasopharyngeal carcinoma (NPC) can cause severe disability and even death. This study aimed to estimate the risk of ischemic stroke in this patient population over more than 10 years of follow-up.

METHODS AND MATERIALS

The study cohorts consisted of all patients hospitalized with a principal diagnosis of NPC (n=1094), whereas patients hospitalized for an appendectomy during 1997 and 1998 (n=4376) acted as the control group and surrogate for the general population. Cox proportional hazard model was performed as a means of comparing the stroke-free survival rate between the two cohorts after adjusting for possible confounding and risk factors.

RESULTS

Of the 292 patients with ischemic strokes, 62 (5.7%) were from the NPC cohort and 230 (5.3%) were from the control group. NPC patients ages 35-54 had a 1.66 times (95% CI, 1.16-2.86; p=0.009) higher risk of ischemic stroke after adjusting for patient characteristics, comorbidities, geographic region, urbanization level of residence, and socioeconomic status. There was no statistical difference in ischemic stroke risk between the NPC patients and appendectomy patients ages 55-64 years (hazard ratio=0.87; 95% CI, 0.56-1.33; p=0.524) after adjusting for other factors.

CONCLUSIONS

Young NPC patients carry a higher risk for ischemic stroke than the general population. Besides regular examinations of carotid duplex, different irradiation strategies or using new technique of radiotherapy, such as intensity modulated radiation therapy or volumetric modulated arc therapy, should be considered in young NPC patients.

Stroke Prevalence in a Poor Neighbourhood of SãO Paulo, Brazil: Applying a Stroke Symptom Questionnaire

Background

Brazil has one of the highest stroke mortality rates in the world, these rates are most endemic in the poor. We verified the prevalence of stroke in a deprived neighbourhood in the city of São Paulo, Brazil and compared it with other surveys worldwide.

Methods

A questionnaire with six questions concerning limb and facial weakness, articulation, sensory disturbances, impaired vision, and past diagnosis of stroke was completed door-to-door in a well-defined area of 15 000 people. Questionnaires were considered positive when a participant answered two or more questions about stroke symptoms or the presence of stroke being confirmed by a physician, or at least three questions in the positive, even if not confirmed by a doctor.

Results

Of the 4496 individuals over 35-years old living in the area, 243 initially screened positive for stroke. The age-adjusted prevalence rate for men was 4·6% (95% confidence interval 3·5–5·7). For women, the prevalence rate was 6·5% (95% confidence interval 5·5–7·5); when considering only one question, the rate was 4·8% (95% confidence interval 3·9–5·7). The most commonly reported symptoms were limb weakness and sensory disturbances. Hypertension and heart disease were the conditions most commonly associated with previous stroke.

Conclusion

Stroke prevalence rates were higher in this poor neighbourhood compared with other surveys.

Risk of Stroke in Patients Hospitalized for Isolated Vertigo

Background and Purpose—

Vertigo is a common presenting symptom in ambulatory care settings, and stroke is its leading and most challenging concern. This study aimed to determine the risk of stroke in vertigo patients in a 4-year follow-up after hospitalization for acute isolated vertigo.

Methods—

The study cohorts consisted of all patients hospitalized with a principal diagnosis of vertigo (n=3021), whereas patients hospitalized for an appendectomy in 2004 (n=3021) comprised the control group and surrogate for the general population. Cox proportional hazard model was performed as a means of comparing the 4-year stroke-free survival rate between the 2 cohorts after adjusting for possible confounding and risk factors. Among vertigo patients, there was further stratification for risk factors to identify the group at high risk for stroke.

Results—

Of the 243 stroke patients, 185 (6.1%) were from the study cohort and 58 (1.9%) were from the control group. Comparing the 2 groups, patients with vertigo symptoms had a 3.01-times (95% CI, 2.20–4.11; P <0.001) higher risk for stroke after adjusting for patient characteristics, comorbidities, geographic region, urbanization level of residence, and socioeconomic status. Vertigo patients with ≥3 risk factors had a 5.51-fold higher risk for stroke (95% CI, 3.10–9.79; P <0.001) than those without risk factors.

Conclusions—

Vertigo patients are at higher risk for stroke than the general population. They should have a comprehensive neurological examination, vascular risk factors survey, and regular follow-up for several years after hospital discharge after treatment of isolated vertigo.

Level of urbanization and noncommunicable disease risk factors in Tamil Nadu, India

OBJECTIVE

To investigate the poorly understood relationship between the process of urbanization and noncommunicable diseases (NCDs) through the application of a quantitative measure of urbanicity.

METHODS

We constructed a measure of the urban environment for seven areas using a seven-item scale based on data from the Census of India 2001 to develop an "urbanicity" scale. The scale was used in conjunction with data collected from 3705 participants in the World Health Organization's 2003 STEPwise risk factor surveillance survey in Tamil Nadu, India, to analyse the relationship between the urban environment and major NCD risk factors. Linear and logistic regression models were constructed examining the relationship between urbanicity and chronic disease risk.

FINDINGS

Among men, urbanicity was positively associated with smoking (odds ratio: 3.54; 95% confidence interval, CI: 2.4-5.1), body mass index (OR: 7.32; 95% CI: 4.0-13.6), blood pressure (OR: 1.92; 95% CI: 1.4-2.7) and low physical activity (OR: 3.26; 95% CI: 2.5-4.3). Among women, urbanicity was positively associated with low physical activity (OR: 4.13; 95% CI: 3.0-5.7) and high body mass index (OR: 6.48; 95% CI: 4.6-9.2). In both sexes urbanicity was positively associated with the mean number of servings of fruit and vegetables consumed per day (P < 0.05).

CONCLUSION

Urbanicity is associated with the prevalence of several NCD risk factors in Tamil Nadu, India.

Increased risk of stroke after a herpes zoster attack: a population-based follow-up study

BACKGROUND AND PURPOSE

Varicella zoster virus-induced vasculopathy and postherpes zoster attack stroke syndromes have been reported previously; nevertheless, data regarding the exact prevalence and risk of stroke occurring postherpes zoster attack are still lacking. This study aims to investigate the frequency and risk of stroke after a herpes zoster attack using a nationwide, population-based study of a retrospective cohort design. Method- A total of 7760 patients who had received treatment for herpes zoster between 1997 and 2001 were included and matched with 23 280 randomly selected subjects. A 1-year stroke-free survival rate was then estimated using the Kaplan-Meier method. After adjusting for potential confounders, Cox proportional hazard regressions were carried out to compute the adjusted 1-year survival rate.

RESULTS

Of the sampled patients, 439 patients (1.41%) developed strokes within the 1-year follow-up period, that is, 133 individuals (1.71% of the patients with herpes zoster) from the study cohort and 306 individuals (1.31% of patients in the comparison cohort) from the comparison cohort. The log rank test indicated that patients with herpes zoster had significantly lower 1-year stroke-free survival rates than the control (P<0.001). The adjusted hazard ratios of stroke after herpes zoster and herpes zoster ophthalmicus during the 1-year follow-up period were 1.31 and 4.28, respectively.

CONCLUSIONS

The risk for stroke increased after a zoster attack. Although varicella zoster virus vasculopathy is a well-documented complication that may induce a stroke postherpes zoster attack, it does not fully account for the unexpectedly high risk of stroke in these patients.

Sex differences in stroke epidemiology: a systematic review

BACKGROUND AND PURPOSE

Epidemiological studies, mainly based on Western European surveys, have shown that stroke is more common in men than in women. In recent years, sex-specific data on stroke incidence, prevalence, subtypes, severity and case-fatality have become available from other parts of the world. The purpose of this article is to give a worldwide review on sex differences in stroke epidemiology.

METHODS

We searched PubMed, tables-of-contents, review articles, and reference lists for community-based studies including information on sex differences. In some areas, such as secular trends, ischemic subtypes and stroke severity, noncommunity-based studies were also reviewed. Male/female ratios were calculated.

RESULTS

We found 98 articles that contained relevant sex-specific information, including 59 incidence studies from 19 countries and 5 continents. The mean age at first-ever stroke was 68.6 years among men, and 72.9 years among women. Male stroke incidence rate was 33% higher and stroke prevalence was 41% higher than the female, with large variations between age bands and between populations. The incidence rates of brain infarction and intracerebral hemorrhage were higher among men, whereas the rate of subarachnoidal hemorrhage was higher among women, although this difference was not statistically significant. Stroke tended to be more severe in women, with a 1-month case fatality of 24.7% compared with 19.7% for men.

CONCLUSIONS

Worldwide, stroke is more common among men, but women are more severely ill. The mismatch between the sexes is larger than previously described.

Urbanization and the likelihood of a cesarean section

OBJECTIVE

This study examines the association between the likelihood of cesarean section (CS) and the degree of urbanization in Taiwan, exploring possible explanations for the difference.

STUDY DESIGN

The database used in this study was the Taiwan 2004 National Health Insurance Research Database. A total of 200,207 singleton deliveries fulfilled our criteria and were included in our study. The urbanization level of cities/towns where parturients resided at the time of delivery was stratified into seven categories. A multilevel logistic regression model was applied to examine the relative likelihood of CS by urbanization level after adjusting for parturient, physician and hospital characteristics.

RESULTS

There was an upward trend in the CS rate with advancing urbanization level; the CS rates for urbanization level 1 (most urbanized) through 7 (least urbanized) were 33.7, 32.3, 30.4, 30.2 29.7, 29.5, and 28.6%, respectively. Compared with participants living at the highest urbanization level, the adjusted odds of a CS were 0.91 (95% CI=0.85-0.98, p=0.014), 0.84 (95% CI=0.78-0.91, p<0.001), 0.83 (95% CI=0.68-0.88, p<0.001), 0.79 (95% CI=0.72-0.86, p<0.001), and 0.70 (95% CI=0.62-0.80, p<0.001) times, respectively, for those living in cities/towns ranked from the third highest to the lowest levels of urbanization.

CONCLUSIONS

We conclude that higher urbanization levels were associated with higher odds of CS. Highly urbanized communities could therefore be targeted for policy intervention aimed at reducing the unnecessary CS rate.

Sudden sensorineural hearing loss increases the risk of stroke: a 5-year follow-up study

BACKGROUND AND PURPOSE

No previous study has investigated the incidence or risk of cerebrovascular diseases developing after the sudden sensorineural hearing loss (SSNHL). This study sets out to estimate the risk of stroke development among SSNHL patients during a 5e-year follow-up period after hospitalization for acute episodes of SSNHL.

METHODS

Our study design features a study cohort and a comparison cohort. The study cohort consists of all patients hospitalized with a principal diagnosis of sudden hearing loss (n=1,423), whereas the control cohort comprised all patients hospitalized for an appendectomy in 1998 (n=5692) as a surrogate for the general population. Each patient was tracked from hospitalization in 1998 until the end of 2003. Cox proportional hazard regressions were performed as a means of computing the 5-year stroke-free survival rates after adjustment for possible confounding factors.

RESULTS

Of the total sample, 621 patients (8.7%) had strokes during the 5-year follow-up period: 180 (12.7% of the SSNHL patients) from the study cohort and 441 (7.8% of patients undergoing an appendectomy) from the control cohort. After adjusting for other factors, the hazard of stroke during the 5-year follow-up period was 1.64-times (95% CI, 1.31 to 2.07; P<0.001) greater for SSNHL patients than for appendectomy patients.

CONCLUSIONS

Our findings suggest that SSNHL can be an early warning sign of impending stroke. We suggest that SSNHL patients should undergo a comprehensive hematologic and neurological examination to help clinicians identify those potentially at risk for stroke developing in the near future.

Increased risk of stroke in patients who undergo cesarean section delivery: a nationwide population-based study

OBJECTIVE

This study used a population-based dataset to determine whether (compared with vaginal deliveries), cesarean section deliveries increase the risk of postpartum stroke during the 3-, 6-, or 12-month period after delivery.

STUDY DESIGN

This study used 1998-2003 records from the Taiwan National Health Insurance Research Database for 987,010 women with singleton deliveries from 1998-2002. Cox proportional hazard regressions were carried out to compute stroke-free survival rates between the 2 delivery modes.

RESULTS

The regression model indicated that, compared with patients who delivered vaginally, the hazard ratio for postpartum stroke among those who delivered by cesarean section was 1.67 times greater within 3 months of delivery (95% CI, 1.29-2.16), was 1.61 times greater within 6 months of delivery (95% CI, 1.31-1.98), and was 1.49 times greater within 12 months of delivery (95% CI, 1.27-1.76).

CONCLUSION

Our data indicates that cesarean section delivery is an independent risk factor for stroke.