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Gender Differences in Stroke Care and Outcomes in Ontario
Women's Health Issues 21-2 (2011) 171–176
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Original article
Gender Differences in Stroke Care and Outcomes in Ontario Moira K. Kapral, MD, MSc, FRCPC a,b,c,d,g,*, Naushaba Degani, PhD i, Ruth Hall, BASc, MSc, PhD c, Jiming Fang, PhD c,g, Gustavo Saposnik, MD, MSc, FAHA a,b,e, Janice Richards, RN, BA c, Frank L. Silver, MD, FRCPC a,f,g, Annette Robertson, RN, BScN c, Arlene S. Bierman, MD, MS, FRCPC a,b,c,h,i a
Department of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada d Division of General Internal Medicine and Clinical Epidemiology, and Women’s Health Program, University Health Network, Toronto, Ontario, Canada e Stroke Research Unit, Division of Neurology, Department of Medicine, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada f Division of Neurology, University Health Network, Toronto, Ontario, Canada g Canadian Stroke Network, Ottawa, Canada h Lawrence M. Bloomberg Faculty of Nursing, University of Toronto, Toronto, Ontario, Canada i Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada b c
Article history: Received 12 April 2010; Received in revised form 12 October 2010; Accepted 14 October 2010
a b s t r a c t Background: Studies of potential gender differences in stroke care and outcomes have yielded inconsistent findings. The Project for an Ontario Women’s Health Evidence-based Report study measured established stroke care indicators in a large, representative sample of women and men with stroke or transient ischemic attack (TIA) admitted to acute care institutions in the province of Ontario, Canada. Methods: The Registry of the Canadian Stroke Network performs a biennial audit on a random sample of 20% of patients with stroke or TIA seen at more than 150 acute care institutions across Ontario. We used data from the 2004/05 audit to compare stroke care by gender, with stratification by age and neighborhood income. Results: The sample consisted of 4,046 patients (51% women). There were no significant gender differences in the use of thrombolysis, neuroimaging, carotid imaging, dysphagia screening, antithrombotic therapy, or neurology and other consultations. Women with ischemic stroke or TIA were less likely than men to be prescribed statins or undergo carotid imaging and endarterectomy within 6 months of stroke; women were more likely than men to receive antihypertensives. There were no significant gender differences in readmission or mortality rates after stroke. Interpretation: In this population-based study, we found little evidence of gender differences in stroke care or outcomes other than lipid-lowering therapy, carotid imaging, and endarterectomy. Further study is needed to assess the contribution of the provincial stroke strategy in eliminating gender differences in management of acute stroke and to better understand and target remaining gender differences in management. Copyright Ó 2011 by the Jacobs Institute of Women’s Health. Published by Elsevier Inc.
This report does not necessarily reflect the views of Echo or the Ontario Ministry of Health and Long-Term Care or any other supporting or sponsoring institution. The Project for an Ontario Women’s Health Evidence-based Report (POWER) Study is funded by Echo: Improving Women’s Health in Ontario, an agency of the Ontario Ministry of Health and Long-Term Care. The Registry of the Canadian Stroke Network is funded by the Canadian Stroke Network and the Ontario Ministry of Health and Long-Term Care. The Institute for Clinical Evaluative Sciences is supported by an operating grant from the Ontario Ministry of Health and Long-Term Care. Dr. Kapral is supported by a New Investigator Award from
the Canadian Institutes for Health Research (CIHR), as well as career support from the Canadian Stroke Network and the University Health Network Women’s Health Program, and is a member of the GENESIS (Gender and Sex Determinants of Circulatory and Respiratory Diseases): Interdisciplinary Enhancement Teams Grant Program, Canadian Institutes of Health Research and the Heart and Stroke Foundation of Canada. * Correspondence to: Dr. Moira K. Kapral, Toronto General Hospital, 200 Elizabeth St. 14 Eaton North, Room 215, Toronto, Ontario, Canada M5G 2C4. Phone: 416-340-4642. fax: 416-595-5826. E-mail address: [email protected] (M.K. Kapral).
1049-3867/$ - see front matter Copyright Ó 2011 by the Jacobs Institute of Women’s Health. Published by Elsevier Inc. doi:10.1016/j.whi.2010.10.002
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Introduction Stroke is a leading cause of death and disability in women and men worldwide (Rosamond et al., 2007). Fortunately, effective treatments exist for improving stroke outcomes and for reducing the risk of stroke recurrence. Acute interventions such as thrombolysis and organized in-patient stroke care have been shown to decrease the risk of disability following stroke, and antithrombotic therapy, management of hypertension, lipidlowering therapy, and carotid endarterectomy decrease the risk of recurrent stroke in appropriately selected patients (Rothwell et al., 2003; Saxena & Koudstaal, 2004; Stroke Unit Trialists’ Collaboration, 2007; Wardlaw, del Zoppo, & Yamaguchi, 2000). Significant gender differences have been found in the management and outcomes of patients with cardiac disease, with studies showing that women are less likely than men to undergo diagnostic testing or receive interventions such as thrombolysis, care in an intensive unit, and revascularization procedures (Fowler et al., 2007; Nguyen, Berger, Duval, & Luepker, 2008; Pilote et al., 2007). Given the similarities in risk factors and demographics between individuals with coronary and cerebrovascular disease, it is plausible that similar disparities in care could exist in the setting of stroke. Research to date, however, has yielded inconsistent findings (Di Carlo et al., 2003; Eriksson, Glader, Norrving, Terent, & Stegmayr, 2009; Glader et al., 2003; Kapral et al., 2005; Lewsey et al., 2009; Lisabeth, Roychoudhury, Brown, & Levine, 2004; Muller-Nordhorn et al., 2006; Palnum et al., 2009; Reeves et al., 2009; Roquer, Campello, & Gomis, 2003; Smith, Lisabeth, Brown, & Morgenstern, 2005; Smith, Murphy, Santos, Phillips, & Wilde, 2009). We used data from a population-based audit of hospitalbased stroke care in the province of Ontario, Canada, and compared the use of recommended acute stroke interventions (stroke unit care, thrombolysis, acute antithrombotic therapy, swallowing assessments), interventions for secondary stroke prevention (antihypertensive use, antithrombotic use, lipidlowering therapy, carotid endarterectomy), and outcomes (death, readmissions) in women and men, with stratification by age and income quintile, and with adjustment for other prognostic factors. Materials and Methods Data Sources The Registry of the Canadian Stroke Network performs a biennial audit on a random sample of 20% of all patients with stroke or transient ischemic attack (TIA) seen in the emergency department or admitted to hospital at every acute care institution across the province of Ontario, Canada (Kapral, et al., 2009). For the audit, cases are identified from the Canadian Institute for Health Information (CIHI) Discharge Abstract Database (for admitted patients) and National Ambulatory Care Reporting System (for patients seen in the emergency department but not admitted) using ICD-10 codes I60, I61, I63, I64, and G45 (excluding G45.4). For individuals with more than one stroke/TIA during the sampling time frame, only the first stroke/TIA event is included. From all eligible cases, a simple random sample of 20% of charts is selected, with oversampling at small- and mediumvolume institutions. Centrally trained neurology research nurses perform chart abstraction at participating hospitals using laptop computers and custom software. Chart validation by duplicate chart abstraction has shown excellent agreement
(kappa scores or intra-class correlation coefficients of greater than 0.9) for key variables in the database including age, gender, and carotid imaging (Kapral, et al., 2009). The data collection software has date and value range checks to ensure accurate data entry and “forces” chart abstraction personnel to obtain complete information on age, gender, stroke type, and other key variables before the case record can be submitted for inclusion in the database, ensuring that there are no missing data for these variables. For analyses of processes of stroke care delivery, we used data on patients aged 45 and older captured in the 2004/ 2005 audit, which included patients seen between April 1, 2004, and March 31, 2005. Using unique patient identifiers, the Registry of the Canadian Stroke Network database was linked with the CIHI discharge abstract database for information on carotid endarterectomy procedures (using ICD-10 CCI procedure code 1JE57) and to the 2001 Canada Census for information on neighborhood income. For analyses of mortality and readmissions after stroke, we used the CIHI discharge abstract database to identify all hospital separations for stroke or TIA in fiscal 2005/2006, again using ICD-10 codes I60, I61, I63, I64, and G45 (excluding G45.4), and determined 30-day readmissions and mortality through the CIHI discharge abstract database and the Ontario Registered Persons Database, respectively. The Registry of the Canadian Stroke Network and the POWER Study were approved by the Sunnybrook Health Sciences Centre and St. Michael’s Hospital Research Ethics Boards, respectively. Chart abstraction was performed without patient consent, because the primary purpose of the registry is the measuring and monitoring of the quality of stroke care delivery, and the registry has “prescribed person” status under Ontario privacy legislation (Personal Health Information Protection Act, 2004) that waives this requirement.
Selection of Stroke Care Indicators The American Stroke Association, the Canadian Stroke Strategy, and other organizations have published guidelines and best practice recommendations for evidence-based quality stroke care delivery (Lindsay et al., 2005; Adams et al., 2007). After a review of the literature, including these guidelines, and using a modified Delphi process, a technical expert panel convened by the POWER Study selected the following stroke care process indicators for comparisons between women and men (denominators indicated in italics): (1) thrombolysis with tissue plasminogen activator in those with ischemic stroke; (2) admission to an acute stroke unit (patients with stroke (ischemic or hemorrhagic) or TIA, admitted to hospital); (3) carotid imaging in those with ischemic stroke or TIA admitted to hospital; (4) dysphagia screening (patients with stroke (ischemic or hemorrhagic) admitted to hospital); (5) antithrombotic therapy (aspirin, clopidogrel, combination aspirin and dipyridamole, warfarin) in those with ischemic stroke or TIA; (6) warfarin for those with atrial fibrillation and ischemic stroke or TIA. We also evaluated the use of in-hospital consultations from physiotherapy, occupational therapy and speech language pathology (patients with stroke (ischemic or hemorrhagic) admitted to hospital), neurology, and nutrition, the use of antihypertensive therapy and lipid-lowering agents at discharge, and all-cause readmission and mortality rates at 30 days post-stroke (patients with stroke [ischemic or hemorrhagic] or TIA, admitted to hospital).
M.K. Kapral et al. / Women's Health Issues 21-2 (2011) 171–176
Analysis The baseline characteristics of women and men were compared using Rao-Scott chi-square tests for categorical variables and survey regression analysis for continuous variables. Analyses of processes of care for women and men were not risk adjusted, but were first stratified by gender and then further stratified by age and neighborhood income. Analyses of all-cause, 30-day readmissions and mortality were performed with adjustment for age (using indirect standardization), stroke type, and comorbid illness (using multiple logistic regression). Comorbid illness was summarized using the Charlson-Deyo comorbidity index scale, a weighted summary scale of 17 medical conditions. SAS version 9.2 statistical software (SAS, Inc., Cary, NC) was used for all analyses. Results The study sample included 4,046 patients seen between April 1, 2004, and March 31, 2005; 51% were women. The stroke type was ischemic in 52%, TIA in 38%, intracerebral hemorrhage in 8%, and subarachnoid hemorrhage in 3%, with no differences in stroke type or severity between women and men (Table 1). The mean age was 74 years, and women were older than men (75.9 vs. 72.3 years; p < .0001), more likely to reside in neighborhoods with a lower median income, and less likely to be independent before admission (Table 1). Women were more likely than men to have a history of hypertension, and less likely to have hyperlipidemia or to smoke cigarettes (Table 1). The time from stroke onset to hospital presentation was similar for women and men (Table 2). The majority (66%) of patients were admitted to hospital, with no differences between women and men (Table 2). There were no gender differences in Table 1 Baseline Characteristics of Women and Men Seen in the Emergency Department or Admitted to Hospital With Acute Stroke or Transient Ischemic Attack in Ontario, April 1, 2004, to May 31, 2005
n Mean age, yrs Age group, yrs (%) 45–64 65–79 80 Income quintile (%) 1 (lowest) 2 3 4 5 (highest) Independent before admission (%) Living alone (%) Medical history (%) Hypertension Diabetes mellitus Hyperlipidemia Atrial fibrillation Current smoking Stroke type (%) Ischemic stroke Transient ischemic attack Intracerebral hemorrhage Subarachnoid hemorrhage CNS* score <8 (%)
All
Women
Men
p-Value*
4,046 74.1
2,052 75.9
1,994 72.3
<.001
21 43 37
17 39 44
24 46 29
20 22 20 19 18 75 20
23 22 20 18 17 72 27
18 22 20 19 20 79 14
64 24 31 14 14
66 23 28 16 10
61 26 34 13 18
52 38 8 3 27
52 38 7 3 28
52 38 8 3 26
<.001
.014
<.001 <.001 <.001 .044 <.001 .019 <.001 .824
.357
CNS, Canadian Neurological Scale; a score <8 indicates a moderate to severe stroke. * p-Value is for comparison between men and women.
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Table 2 Quality of Care for Women and Men Seen in the Emergency Department or Admitted to Hospital With Acute Stroke or Transient Ischemic Attack in Ontario, April 1, 2004, to May 31, 2005*
Presentation within 2.5 hours (%) Median time to presentation, h Thrombolysis (%) Thrombolysis if presentation to hospital within 2.5 h of stroke onset (%) Admitted to hospital (%) Stroke unit admission (%) Neurology/neurosurgery consultation (%) Neuroimagingy (%) Carotid imagingy (%) Dysphagia screening (%) Physiotherapy (%) Occupational therapy (%) Speech language pathology (%) Nutrition (%) Medications at discharge (%) Antithrombotic agentsy Warfarin for atrial fibrillation Lipid-lowering therapy Antihypertensive agents Carotid endarterectomy within 6 months of index hospitalization (%)
All
Women
Men
p-Value*
33 6.2 4 14
33 6.3 4 14
33 6.0 4 14
.488 .5426 .974 .891
66 19 58 85 52 47 70 61 47 34
67 18 57 85 49 47 70 62 47 34
65 21 60 85 54 47 70 61 47 34
.2300 .127 .215 .872 .004 .812 .891 .758 .717 .715
93 75 45 79 1.5
92 73 41 81 1
93 77 48 76 2
.424 .271 <.001 <.001 <.001
* Denominators are as follows: (1) Presentation within 2.5 hours, median time to presentation, admission to hospitaldpatients seen in the emergency department for stroke or transient ischemic attack; (2) Thrombolysisdpatients seen in the emergency department or admitted to hospital with ischemic stroke; (3) Physiotherapy, occupational therapy, speech language pathology, nutritiondpatients admitted to hospital for stroke; (4) Stroke unit admission, neuroimaging, dysphagia screening, consultations from neurologydpatients admitted to hospital with stroke (any type) or transient ischemic attack; (5) Medications at discharge, carotid endarterectomydpatients admitted to hospital with ischemic stroke or transient ischemic attack, and alive at discharge. p-Values are for comparisons of women and men. y Neuroimaging includes computed tomography (CT) and magnetic resonance (MR) imaging. Carotid imaging includes carotid Doppler, CT angiography, MR angiography, and catheter angiography. Antithrombotic agents include aspirin, clopidogrel, combination aspirin and dipyridamole (Aggrenox), and warfarin.
the majority of the stroke quality indicators studied, including rates of thrombolysis administration, admission to a stroke unit, consultations from neurologists and other stroke team members, neuroimaging, dysphagia screening, and prescription of antithrombotic agents and warfarin at discharge (Table 2). Women with stroke or TIA were less likely than their male counterparts to be prescribed lipid-lowering agents at discharge (41% vs. 47%), to undergo carotid imaging (51% vs. 55%), or to be treated with carotid endarterectomy within 6 months of the index stroke event (1.1% vs. 1.9%), and were more likely to receive antihypertensive therapy at discharge (81% vs. 76%; Table 2). When the analyses were stratified by age group, those aged 80 and older were less likely than their younger counterparts to receive lipid-lowering therapy, carotid imaging, or carotid endarterectomy; with increasing age, there was a trend toward lower rates of thrombolysis, stroke unit care, and warfarin for atrial fibrillation and no difference in rates of neuroimaging or antithrombotic therapy (Figure 1). Those aged 80 and older were more likely than their younger counterparts to receive dysphagia screening, antihypertensive therapy, and assessments by physiotherapy, occupational therapy, and speech language pathology. There were few gender differences in management within age strata and these were similar to gender differences seen in the overall population. There were no differences in management by neighborhood income quintile or by gender within neighborhood income quintiles.
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120 45-64 65-79
Percentage (%)
100
96
80+
87
84
94 91
84
79
80
80 69
59
60
61 61
58 46
47
40 22
20
51 41
39
17
21
14 12
17
0
Str oke unit
tPA
CT/MRI
Carotid imaging*
Dysphagia screen*
ASA
Warfarin
Statins*
tPA indicates thrombolysis with tissue plasminogen activator; CT/MRI indicates neuroimaging with either computed tomography (CT) or magnetic resonance imaging (MRI); carotid imaging includes carotid Doppler ultrasound, CT angiography, MR angiography and catheter angiography; ASA indicates antithrombotic therapy with aspirin, combination aspirin and dipyridamole, clopidogrel or warfarin. *P<0.001 for comparison across age groups Figure 1. In-hospital care for women and men with stroke and TIA, by age group in Ontario, 2004/05.
There were no differences in risk-adjusted 30-day readmission (stroke, cardiovascular, and all-cause readmission) or stroke case-fatality rates between men and women (Figures 2 and 3). Readmission rates were similar across age groups, but stroke case-fatality increased with increasing age, with 30-day mortality rates of 8%, 12%, and 23% in women aged 45 to 64 years, 65 to 79 years, and over 80 years, respectively (Figures 2 and 3).
and nutrition), or use of antithrombotic therapy. However, women were less likely than men to be prescribed lipid-lowering agents, undergo carotid imaging, or be treated with carotid endarterectomy within 6 months of the index stroke event, and were more likely to receive antihypertensive therapy. There were no gender differences in risk-adjusted 30-day all-cause readmission or mortality rates after stroke. Our results are in contrast with those of previous studies from other jurisdictions, which have documented less aggressive care and higher stroke case-fatality rates in women compared with men (Di Carlo et al., 2003; Eriksson et al., 2009; Glader et al., 2003; Lewsey et al., 2009; Lisabeth et al., 2004; Muller-Nordhorn et al., 2006; Palnum et al., 2009; Reeves et al., 2009; Roquer et al., 2003; Smith et al., 2009). However, the lower use of carotid imaging, carotid endarterectomy, and lipid-lowering therapy in women in our study parallel the patterns of gender differences in
Discussion In this population-based study of all acute care institutions across the province of Ontario, Canada, we found no gender differences in the delivery of a number of key stroke care quality indicators, including thrombolysis, neuroimaging, dysphagia screening, stroke unit admission, consultations (from neurology, physiotherapy, occupational therapy, speech language pathology,
Percentage (%)
10 8
9 7
9
9
9
7
6 4
3
3
3 2
2
2
3
3
3
3
3
2
2 0 45-64
65-79
80+
All cause readmissions
45-64
65-79
80+
Stroke readmissions
45-64
65-79
80+
CVD readmissions
Readmission type and Age group (years) Women
Men
Adjusted for stroke type and Charlson comorbidity index score CVD indicates cardiovascular disease (myocardial infarction, congestive heart failure, stroke)
Figure 2. Risk-adjusted 30-day nonelective readmission rates after discharge from hospital for women and men with a primary diagnosis of stroke or TIA in Ontario, by gender and age group.
M.K. Kapral et al. / Women's Health Issues 21-2 (2011) 171–176
Percentage (%)
50 40
Women Men
30
26
23
20
16 12
10
8
8
0 45-64
65-79
80+
A ge group (y ears ) Adjusted for stroke type and Charlson comorbidity index score. The differences in mortality rates within age groups are not statistically significant.
Figure 3. Risk adjusted 30-day mortality among women and men admitted to hospital with a primary diagnosis of stroke or TIA in Ontario, by gender and age group.
revascularization and lipid management observed in multiple previous studies of patients with myocardial infarction (Abramson Bierman et al., 2009; Jneid et al., 2008; Saposnik et al., 2009) as well as stroke (Lewsey et al., 2009; Reeves et al., 2009; Smith et al., 2009). Of note, recent work from our group suggests that some of the observed gender differences in carotid revascularization may be explained by appropriate patient selection based on stroke characteristics, surgical eligibility, and the prevalence of severe carotid stenosis (Kapral, Ben-Yakov, et al., 2009) For both women and men, older age was associated with lower rates of use of warfarin for atrial fibrillation, statin use, carotid imaging, and carotid endarterectomy, and higher rates of dysphagia screening and consultations from rehabilitation services, findings that are consistent with previous research (Fairhead & Rothwell, 2006; Kaplan et al., 2005). It is not known whether the reduced use of some interventions with older age in our cohort is explained by contraindications or other appropriate patient selection criteria, and these findings require further study. Increasing age was also significantly associated with stroke casefatality, highlighting the impact of age on outcomes after stroke (Saposnik et al., 2008). Given the differences between men and women in stroke risk factors and age at presentation, the goals of management should not necessarily be identical treatment for women and men, but rather optimal treatment for each individual patient based on his or her clinical status. Socioeconomic status is known to be associated with stroke incidence and outcomes, with several studies documenting an inverse association between socioeconomic status and stroke incidence, mortality, and case fatality rates (Cox et al., 2006; Jakovljevic et al., 2001; Kapral, Wang, Mamdani, & Tu, 2002; Kleindorfer et al., 2006). It is not known whether the inverse association between socioeconomic status and mortality is due to differences in access to care or to differences in comorbid illness or other risk factors. We found no association between income quintile and any of the stroke quality indicators evaluated. In 2000, the province of Ontario developed a strategy of coordinated and regionalized stroke care delivery, now known as the Ontario Stroke System (Heart and Stroke Foundation of Canada, 2000). The Ontario Stroke System includes the establishment of regional steering committees with a mandate to ensure optimal stroke care across an entire region and regional and district stroke centers with stroke-specific resources and expertise. The activities of the Ontario Stroke System include dissemination of best practice guidelines, patient and provider education, and regular audits and feedback of stroke care delivery through detailed chart audits (Lewis et al., 2006). It is
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likely that this coordinated stroke system has helped to minimize disparities in stroke management and outcomes based on gender, region, and socioeconomic status. Some study limitations deserve comment. We analyzed data from a hospital-based cohort, and thus do not have information on potential gender differences in the care of patients who do not seek hospital attention for stroke syndromes or for those who receive ambulatory care for primary and secondary stroke prevention. However, it should be emphasized that in contrast with most studies based on medical records review, our study sample included not only hospitalized patients, but also those seen in the emergency department but not admitted to hospital. Although we stratified our analyses by age and neighborhood income, we were unable to study other potential social determinants of care and outcomes such as recent immigrancy, race/ ethnicity, and education. In addition, we focused on the quality of acute stroke care delivery, rather than on rehabilitation or reintegration. Previous research has found that women are more likely than men to experience poor functional outcomes, incomplete recovery, and depression after stroke, and our study does not provide data on these important outcome measures (Chong, Lee, Boden-Albala, Paik, & Sacco, 2006; Di Carlo et al., 2003; Glader et al., 2003; Kapral et al., 2005). Our data collection through chart review rather than direct patient interviews and assessments may have led to underestimates of the prevalence of some risk factors such as smoking and hypertension. In addition, we were unable to obtain information on important factors such as body mass index and counseling for smoking cessation. However, chart review is likely to provide valid results for inhospital interventions such as thrombolysis, stroke unit care, and consultations, and our data source is strengthened by the inclusion of important prognostic variables, such as stroke severity, which are not routinely available in administrative databases or other registries. Finally, some patients, particularly those in the oldest age groups, may not receive recommended stroke care interventions because of legitimate contraindications, and we did not address this in our analyses. In conclusion, in this province-wide study, we found lower rates of carotid imaging, carotid endarterectomy, and lipidlowering therapy in women compared with men. These results are consistent with those of multiple previous studies in the area of cardiovascular disease, and deserve further evaluation to determine the root causes and possible solutions. However, we found that most other aspects of stroke care and outcomes were similar for women and men. This somewhat unexpected finding may be in part explained by the presence of an organized provincial stroke care strategy.
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Palnum, K. D., Andersen, G., Ingeman, A., Krog, B. R., Bartels, P., & Johnsen, S. P. (2009). Sex-related differences in quality of care and short-term mortality among patients with acute stroke in Denmark. A nationwide follow-up study. Stroke, 40, 1134–1139. Pilote, L., Dasgupta, K., Guru, V., Humphries, K. H., McGrath, J., Norris, C., et al. (2007). A comprehensive view of sex-specific issues related to cardiovascular disease. Canadian Medical Association Journal, 176, S1–S44. Reeves, M. J., Fonarow, G. C., Zhao, X., Smith, E. E., & Schwamm, L. H., on behalf of the GWTG-Stroke Steering Committee & Investigators. (2009). Quality of care in women with ischemic stroke in the GWTG program. Stroke, 40, 1127–1133. Roquer, J., Campello, A. R., & Gomis, M. (2003). Sex differences in first-ever acute stroke. Stroke, 34, 1581–1585. Rosamond, W., Flegal, K., Friday, G., Furie, K., Go, A., Greenlund, K., et al. (2007). Heart disease and stroke statisticsd2007 update: A report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation, 115, e171. Rothwell, P. M., Eliasziw, M., Gutnikov, S. A., Fox, A. J., Taylor, D. W., Mayberg, M. R., et al. (2003). Analysis of pooled data from the randomised controlled trials of endarterectomy for symptomatic carotid stenosis. Lancet, 361, 107–116. Saposnik, G., Cote, R., Phillips, S., Gubitz, G., Bayer, N., Minuk, J., et al. (2008). Stroke outcome in those over 80: A multicenter cohort study across Canada. Stroke, 39, 2310–2317. Saposnik, G., Goodman, S. G., Leiter, L. A., Yan, R. T., Fitchett, D. H., Bayer, N. H., et al. (2009). Applying the evidence: Do patients with stroke, coronary artery disease, or both achieve similar treatment goals? Stroke, 40, 1417–1424. Saxena, R., & Koudstaal, P.J. (2004). Anticoagulants for preventing stroke in patients with nonrheumatic atrial fibrillation and a history of stroke or transient ischaemic attack. Cochrane Database System Review, 2, CD000185. Smith, D. B., Murphy, P., Santos, P., Phillips, M., & Wilde, M. (2009). Gender differences in the Colorado Stroke Registry. Stroke, 40, 1078–1081. Smith, M. A., Lisabeth, L. D., Brown, D. L., & Morgenstern, L. B. (2005). Gender comparisons of diagnostic evaluation for ischemic stroke patients. Neurology, 65, 855–858. Stroke Unit Trialists’ Collaboration. (2007). Organised inpatient (stroke unit) care for stroke. Cochrane Database System Review, 4, CD000197. Wardlaw, J.M., del Zoppo, G., & Yamaguchi, T. (2000). Thrombolysis for acute ischaemic stroke. Cochrane Database System Review, 2, CD000213.
Author Descriptions Dr. Kapral is an internist and health services researcher in the area of stroke in women.
Drs. Degani and Hall are epidemiologists with expertise in health services research and cardiovascular disease.
Dr. Fang is a biostatistican.
Drs. Silver and Saposnik are stroke neurologists and researchers.
Ms. Robertson and Ms. Richards are research nurses with expertise in cardiovascular disease.
Dr. Bierman, principal investigator of the POWER Study, is OWHC Chair in Women’s Health and Associate Professor, Bloomberg Faculty of Nursing; Health Policy, Evaluation, and Management; and Medicine, University of Toronto; and Scientist, Li Ka Shing Knowledge Institute, St. Michael's Hospital.
www.whijournal.com
Original article
Gender Differences in Stroke Care and Outcomes in Ontario Moira K. Kapral, MD, MSc, FRCPC a,b,c,d,g,*, Naushaba Degani, PhD i, Ruth Hall, BASc, MSc, PhD c, Jiming Fang, PhD c,g, Gustavo Saposnik, MD, MSc, FAHA a,b,e, Janice Richards, RN, BA c, Frank L. Silver, MD, FRCPC a,f,g, Annette Robertson, RN, BScN c, Arlene S. Bierman, MD, MS, FRCPC a,b,c,h,i a
Department of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada d Division of General Internal Medicine and Clinical Epidemiology, and Women’s Health Program, University Health Network, Toronto, Ontario, Canada e Stroke Research Unit, Division of Neurology, Department of Medicine, St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada f Division of Neurology, University Health Network, Toronto, Ontario, Canada g Canadian Stroke Network, Ottawa, Canada h Lawrence M. Bloomberg Faculty of Nursing, University of Toronto, Toronto, Ontario, Canada i Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada b c
Article history: Received 12 April 2010; Received in revised form 12 October 2010; Accepted 14 October 2010
a b s t r a c t Background: Studies of potential gender differences in stroke care and outcomes have yielded inconsistent findings. The Project for an Ontario Women’s Health Evidence-based Report study measured established stroke care indicators in a large, representative sample of women and men with stroke or transient ischemic attack (TIA) admitted to acute care institutions in the province of Ontario, Canada. Methods: The Registry of the Canadian Stroke Network performs a biennial audit on a random sample of 20% of patients with stroke or TIA seen at more than 150 acute care institutions across Ontario. We used data from the 2004/05 audit to compare stroke care by gender, with stratification by age and neighborhood income. Results: The sample consisted of 4,046 patients (51% women). There were no significant gender differences in the use of thrombolysis, neuroimaging, carotid imaging, dysphagia screening, antithrombotic therapy, or neurology and other consultations. Women with ischemic stroke or TIA were less likely than men to be prescribed statins or undergo carotid imaging and endarterectomy within 6 months of stroke; women were more likely than men to receive antihypertensives. There were no significant gender differences in readmission or mortality rates after stroke. Interpretation: In this population-based study, we found little evidence of gender differences in stroke care or outcomes other than lipid-lowering therapy, carotid imaging, and endarterectomy. Further study is needed to assess the contribution of the provincial stroke strategy in eliminating gender differences in management of acute stroke and to better understand and target remaining gender differences in management. Copyright Ó 2011 by the Jacobs Institute of Women’s Health. Published by Elsevier Inc.
This report does not necessarily reflect the views of Echo or the Ontario Ministry of Health and Long-Term Care or any other supporting or sponsoring institution. The Project for an Ontario Women’s Health Evidence-based Report (POWER) Study is funded by Echo: Improving Women’s Health in Ontario, an agency of the Ontario Ministry of Health and Long-Term Care. The Registry of the Canadian Stroke Network is funded by the Canadian Stroke Network and the Ontario Ministry of Health and Long-Term Care. The Institute for Clinical Evaluative Sciences is supported by an operating grant from the Ontario Ministry of Health and Long-Term Care. Dr. Kapral is supported by a New Investigator Award from
the Canadian Institutes for Health Research (CIHR), as well as career support from the Canadian Stroke Network and the University Health Network Women’s Health Program, and is a member of the GENESIS (Gender and Sex Determinants of Circulatory and Respiratory Diseases): Interdisciplinary Enhancement Teams Grant Program, Canadian Institutes of Health Research and the Heart and Stroke Foundation of Canada. * Correspondence to: Dr. Moira K. Kapral, Toronto General Hospital, 200 Elizabeth St. 14 Eaton North, Room 215, Toronto, Ontario, Canada M5G 2C4. Phone: 416-340-4642. fax: 416-595-5826. E-mail address: [email protected] (M.K. Kapral).
1049-3867/$ - see front matter Copyright Ó 2011 by the Jacobs Institute of Women’s Health. Published by Elsevier Inc. doi:10.1016/j.whi.2010.10.002
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Introduction Stroke is a leading cause of death and disability in women and men worldwide (Rosamond et al., 2007). Fortunately, effective treatments exist for improving stroke outcomes and for reducing the risk of stroke recurrence. Acute interventions such as thrombolysis and organized in-patient stroke care have been shown to decrease the risk of disability following stroke, and antithrombotic therapy, management of hypertension, lipidlowering therapy, and carotid endarterectomy decrease the risk of recurrent stroke in appropriately selected patients (Rothwell et al., 2003; Saxena & Koudstaal, 2004; Stroke Unit Trialists’ Collaboration, 2007; Wardlaw, del Zoppo, & Yamaguchi, 2000). Significant gender differences have been found in the management and outcomes of patients with cardiac disease, with studies showing that women are less likely than men to undergo diagnostic testing or receive interventions such as thrombolysis, care in an intensive unit, and revascularization procedures (Fowler et al., 2007; Nguyen, Berger, Duval, & Luepker, 2008; Pilote et al., 2007). Given the similarities in risk factors and demographics between individuals with coronary and cerebrovascular disease, it is plausible that similar disparities in care could exist in the setting of stroke. Research to date, however, has yielded inconsistent findings (Di Carlo et al., 2003; Eriksson, Glader, Norrving, Terent, & Stegmayr, 2009; Glader et al., 2003; Kapral et al., 2005; Lewsey et al., 2009; Lisabeth, Roychoudhury, Brown, & Levine, 2004; Muller-Nordhorn et al., 2006; Palnum et al., 2009; Reeves et al., 2009; Roquer, Campello, & Gomis, 2003; Smith, Lisabeth, Brown, & Morgenstern, 2005; Smith, Murphy, Santos, Phillips, & Wilde, 2009). We used data from a population-based audit of hospitalbased stroke care in the province of Ontario, Canada, and compared the use of recommended acute stroke interventions (stroke unit care, thrombolysis, acute antithrombotic therapy, swallowing assessments), interventions for secondary stroke prevention (antihypertensive use, antithrombotic use, lipidlowering therapy, carotid endarterectomy), and outcomes (death, readmissions) in women and men, with stratification by age and income quintile, and with adjustment for other prognostic factors. Materials and Methods Data Sources The Registry of the Canadian Stroke Network performs a biennial audit on a random sample of 20% of all patients with stroke or transient ischemic attack (TIA) seen in the emergency department or admitted to hospital at every acute care institution across the province of Ontario, Canada (Kapral, et al., 2009). For the audit, cases are identified from the Canadian Institute for Health Information (CIHI) Discharge Abstract Database (for admitted patients) and National Ambulatory Care Reporting System (for patients seen in the emergency department but not admitted) using ICD-10 codes I60, I61, I63, I64, and G45 (excluding G45.4). For individuals with more than one stroke/TIA during the sampling time frame, only the first stroke/TIA event is included. From all eligible cases, a simple random sample of 20% of charts is selected, with oversampling at small- and mediumvolume institutions. Centrally trained neurology research nurses perform chart abstraction at participating hospitals using laptop computers and custom software. Chart validation by duplicate chart abstraction has shown excellent agreement
(kappa scores or intra-class correlation coefficients of greater than 0.9) for key variables in the database including age, gender, and carotid imaging (Kapral, et al., 2009). The data collection software has date and value range checks to ensure accurate data entry and “forces” chart abstraction personnel to obtain complete information on age, gender, stroke type, and other key variables before the case record can be submitted for inclusion in the database, ensuring that there are no missing data for these variables. For analyses of processes of stroke care delivery, we used data on patients aged 45 and older captured in the 2004/ 2005 audit, which included patients seen between April 1, 2004, and March 31, 2005. Using unique patient identifiers, the Registry of the Canadian Stroke Network database was linked with the CIHI discharge abstract database for information on carotid endarterectomy procedures (using ICD-10 CCI procedure code 1JE57) and to the 2001 Canada Census for information on neighborhood income. For analyses of mortality and readmissions after stroke, we used the CIHI discharge abstract database to identify all hospital separations for stroke or TIA in fiscal 2005/2006, again using ICD-10 codes I60, I61, I63, I64, and G45 (excluding G45.4), and determined 30-day readmissions and mortality through the CIHI discharge abstract database and the Ontario Registered Persons Database, respectively. The Registry of the Canadian Stroke Network and the POWER Study were approved by the Sunnybrook Health Sciences Centre and St. Michael’s Hospital Research Ethics Boards, respectively. Chart abstraction was performed without patient consent, because the primary purpose of the registry is the measuring and monitoring of the quality of stroke care delivery, and the registry has “prescribed person” status under Ontario privacy legislation (Personal Health Information Protection Act, 2004) that waives this requirement.
Selection of Stroke Care Indicators The American Stroke Association, the Canadian Stroke Strategy, and other organizations have published guidelines and best practice recommendations for evidence-based quality stroke care delivery (Lindsay et al., 2005; Adams et al., 2007). After a review of the literature, including these guidelines, and using a modified Delphi process, a technical expert panel convened by the POWER Study selected the following stroke care process indicators for comparisons between women and men (denominators indicated in italics): (1) thrombolysis with tissue plasminogen activator in those with ischemic stroke; (2) admission to an acute stroke unit (patients with stroke (ischemic or hemorrhagic) or TIA, admitted to hospital); (3) carotid imaging in those with ischemic stroke or TIA admitted to hospital; (4) dysphagia screening (patients with stroke (ischemic or hemorrhagic) admitted to hospital); (5) antithrombotic therapy (aspirin, clopidogrel, combination aspirin and dipyridamole, warfarin) in those with ischemic stroke or TIA; (6) warfarin for those with atrial fibrillation and ischemic stroke or TIA. We also evaluated the use of in-hospital consultations from physiotherapy, occupational therapy and speech language pathology (patients with stroke (ischemic or hemorrhagic) admitted to hospital), neurology, and nutrition, the use of antihypertensive therapy and lipid-lowering agents at discharge, and all-cause readmission and mortality rates at 30 days post-stroke (patients with stroke [ischemic or hemorrhagic] or TIA, admitted to hospital).
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Analysis The baseline characteristics of women and men were compared using Rao-Scott chi-square tests for categorical variables and survey regression analysis for continuous variables. Analyses of processes of care for women and men were not risk adjusted, but were first stratified by gender and then further stratified by age and neighborhood income. Analyses of all-cause, 30-day readmissions and mortality were performed with adjustment for age (using indirect standardization), stroke type, and comorbid illness (using multiple logistic regression). Comorbid illness was summarized using the Charlson-Deyo comorbidity index scale, a weighted summary scale of 17 medical conditions. SAS version 9.2 statistical software (SAS, Inc., Cary, NC) was used for all analyses. Results The study sample included 4,046 patients seen between April 1, 2004, and March 31, 2005; 51% were women. The stroke type was ischemic in 52%, TIA in 38%, intracerebral hemorrhage in 8%, and subarachnoid hemorrhage in 3%, with no differences in stroke type or severity between women and men (Table 1). The mean age was 74 years, and women were older than men (75.9 vs. 72.3 years; p < .0001), more likely to reside in neighborhoods with a lower median income, and less likely to be independent before admission (Table 1). Women were more likely than men to have a history of hypertension, and less likely to have hyperlipidemia or to smoke cigarettes (Table 1). The time from stroke onset to hospital presentation was similar for women and men (Table 2). The majority (66%) of patients were admitted to hospital, with no differences between women and men (Table 2). There were no gender differences in Table 1 Baseline Characteristics of Women and Men Seen in the Emergency Department or Admitted to Hospital With Acute Stroke or Transient Ischemic Attack in Ontario, April 1, 2004, to May 31, 2005
n Mean age, yrs Age group, yrs (%) 45–64 65–79 80 Income quintile (%) 1 (lowest) 2 3 4 5 (highest) Independent before admission (%) Living alone (%) Medical history (%) Hypertension Diabetes mellitus Hyperlipidemia Atrial fibrillation Current smoking Stroke type (%) Ischemic stroke Transient ischemic attack Intracerebral hemorrhage Subarachnoid hemorrhage CNS* score <8 (%)
All
Women
Men
p-Value*
4,046 74.1
2,052 75.9
1,994 72.3
<.001
21 43 37
17 39 44
24 46 29
20 22 20 19 18 75 20
23 22 20 18 17 72 27
18 22 20 19 20 79 14
64 24 31 14 14
66 23 28 16 10
61 26 34 13 18
52 38 8 3 27
52 38 7 3 28
52 38 8 3 26
<.001
.014
<.001 <.001 <.001 .044 <.001 .019 <.001 .824
.357
CNS, Canadian Neurological Scale; a score <8 indicates a moderate to severe stroke. * p-Value is for comparison between men and women.
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Table 2 Quality of Care for Women and Men Seen in the Emergency Department or Admitted to Hospital With Acute Stroke or Transient Ischemic Attack in Ontario, April 1, 2004, to May 31, 2005*
Presentation within 2.5 hours (%) Median time to presentation, h Thrombolysis (%) Thrombolysis if presentation to hospital within 2.5 h of stroke onset (%) Admitted to hospital (%) Stroke unit admission (%) Neurology/neurosurgery consultation (%) Neuroimagingy (%) Carotid imagingy (%) Dysphagia screening (%) Physiotherapy (%) Occupational therapy (%) Speech language pathology (%) Nutrition (%) Medications at discharge (%) Antithrombotic agentsy Warfarin for atrial fibrillation Lipid-lowering therapy Antihypertensive agents Carotid endarterectomy within 6 months of index hospitalization (%)
All
Women
Men
p-Value*
33 6.2 4 14
33 6.3 4 14
33 6.0 4 14
.488 .5426 .974 .891
66 19 58 85 52 47 70 61 47 34
67 18 57 85 49 47 70 62 47 34
65 21 60 85 54 47 70 61 47 34
.2300 .127 .215 .872 .004 .812 .891 .758 .717 .715
93 75 45 79 1.5
92 73 41 81 1
93 77 48 76 2
.424 .271 <.001 <.001 <.001
* Denominators are as follows: (1) Presentation within 2.5 hours, median time to presentation, admission to hospitaldpatients seen in the emergency department for stroke or transient ischemic attack; (2) Thrombolysisdpatients seen in the emergency department or admitted to hospital with ischemic stroke; (3) Physiotherapy, occupational therapy, speech language pathology, nutritiondpatients admitted to hospital for stroke; (4) Stroke unit admission, neuroimaging, dysphagia screening, consultations from neurologydpatients admitted to hospital with stroke (any type) or transient ischemic attack; (5) Medications at discharge, carotid endarterectomydpatients admitted to hospital with ischemic stroke or transient ischemic attack, and alive at discharge. p-Values are for comparisons of women and men. y Neuroimaging includes computed tomography (CT) and magnetic resonance (MR) imaging. Carotid imaging includes carotid Doppler, CT angiography, MR angiography, and catheter angiography. Antithrombotic agents include aspirin, clopidogrel, combination aspirin and dipyridamole (Aggrenox), and warfarin.
the majority of the stroke quality indicators studied, including rates of thrombolysis administration, admission to a stroke unit, consultations from neurologists and other stroke team members, neuroimaging, dysphagia screening, and prescription of antithrombotic agents and warfarin at discharge (Table 2). Women with stroke or TIA were less likely than their male counterparts to be prescribed lipid-lowering agents at discharge (41% vs. 47%), to undergo carotid imaging (51% vs. 55%), or to be treated with carotid endarterectomy within 6 months of the index stroke event (1.1% vs. 1.9%), and were more likely to receive antihypertensive therapy at discharge (81% vs. 76%; Table 2). When the analyses were stratified by age group, those aged 80 and older were less likely than their younger counterparts to receive lipid-lowering therapy, carotid imaging, or carotid endarterectomy; with increasing age, there was a trend toward lower rates of thrombolysis, stroke unit care, and warfarin for atrial fibrillation and no difference in rates of neuroimaging or antithrombotic therapy (Figure 1). Those aged 80 and older were more likely than their younger counterparts to receive dysphagia screening, antihypertensive therapy, and assessments by physiotherapy, occupational therapy, and speech language pathology. There were few gender differences in management within age strata and these were similar to gender differences seen in the overall population. There were no differences in management by neighborhood income quintile or by gender within neighborhood income quintiles.
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120 45-64 65-79
Percentage (%)
100
96
80+
87
84
94 91
84
79
80
80 69
59
60
61 61
58 46
47
40 22
20
51 41
39
17
21
14 12
17
0
Str oke unit
tPA
CT/MRI
Carotid imaging*
Dysphagia screen*
ASA
Warfarin
Statins*
tPA indicates thrombolysis with tissue plasminogen activator; CT/MRI indicates neuroimaging with either computed tomography (CT) or magnetic resonance imaging (MRI); carotid imaging includes carotid Doppler ultrasound, CT angiography, MR angiography and catheter angiography; ASA indicates antithrombotic therapy with aspirin, combination aspirin and dipyridamole, clopidogrel or warfarin. *P<0.001 for comparison across age groups Figure 1. In-hospital care for women and men with stroke and TIA, by age group in Ontario, 2004/05.
There were no differences in risk-adjusted 30-day readmission (stroke, cardiovascular, and all-cause readmission) or stroke case-fatality rates between men and women (Figures 2 and 3). Readmission rates were similar across age groups, but stroke case-fatality increased with increasing age, with 30-day mortality rates of 8%, 12%, and 23% in women aged 45 to 64 years, 65 to 79 years, and over 80 years, respectively (Figures 2 and 3).
and nutrition), or use of antithrombotic therapy. However, women were less likely than men to be prescribed lipid-lowering agents, undergo carotid imaging, or be treated with carotid endarterectomy within 6 months of the index stroke event, and were more likely to receive antihypertensive therapy. There were no gender differences in risk-adjusted 30-day all-cause readmission or mortality rates after stroke. Our results are in contrast with those of previous studies from other jurisdictions, which have documented less aggressive care and higher stroke case-fatality rates in women compared with men (Di Carlo et al., 2003; Eriksson et al., 2009; Glader et al., 2003; Lewsey et al., 2009; Lisabeth et al., 2004; Muller-Nordhorn et al., 2006; Palnum et al., 2009; Reeves et al., 2009; Roquer et al., 2003; Smith et al., 2009). However, the lower use of carotid imaging, carotid endarterectomy, and lipid-lowering therapy in women in our study parallel the patterns of gender differences in
Discussion In this population-based study of all acute care institutions across the province of Ontario, Canada, we found no gender differences in the delivery of a number of key stroke care quality indicators, including thrombolysis, neuroimaging, dysphagia screening, stroke unit admission, consultations (from neurology, physiotherapy, occupational therapy, speech language pathology,
Percentage (%)
10 8
9 7
9
9
9
7
6 4
3
3
3 2
2
2
3
3
3
3
3
2
2 0 45-64
65-79
80+
All cause readmissions
45-64
65-79
80+
Stroke readmissions
45-64
65-79
80+
CVD readmissions
Readmission type and Age group (years) Women
Men
Adjusted for stroke type and Charlson comorbidity index score CVD indicates cardiovascular disease (myocardial infarction, congestive heart failure, stroke)
Figure 2. Risk-adjusted 30-day nonelective readmission rates after discharge from hospital for women and men with a primary diagnosis of stroke or TIA in Ontario, by gender and age group.
M.K. Kapral et al. / Women's Health Issues 21-2 (2011) 171–176
Percentage (%)
50 40
Women Men
30
26
23
20
16 12
10
8
8
0 45-64
65-79
80+
A ge group (y ears ) Adjusted for stroke type and Charlson comorbidity index score. The differences in mortality rates within age groups are not statistically significant.
Figure 3. Risk adjusted 30-day mortality among women and men admitted to hospital with a primary diagnosis of stroke or TIA in Ontario, by gender and age group.
revascularization and lipid management observed in multiple previous studies of patients with myocardial infarction (Abramson Bierman et al., 2009; Jneid et al., 2008; Saposnik et al., 2009) as well as stroke (Lewsey et al., 2009; Reeves et al., 2009; Smith et al., 2009). Of note, recent work from our group suggests that some of the observed gender differences in carotid revascularization may be explained by appropriate patient selection based on stroke characteristics, surgical eligibility, and the prevalence of severe carotid stenosis (Kapral, Ben-Yakov, et al., 2009) For both women and men, older age was associated with lower rates of use of warfarin for atrial fibrillation, statin use, carotid imaging, and carotid endarterectomy, and higher rates of dysphagia screening and consultations from rehabilitation services, findings that are consistent with previous research (Fairhead & Rothwell, 2006; Kaplan et al., 2005). It is not known whether the reduced use of some interventions with older age in our cohort is explained by contraindications or other appropriate patient selection criteria, and these findings require further study. Increasing age was also significantly associated with stroke casefatality, highlighting the impact of age on outcomes after stroke (Saposnik et al., 2008). Given the differences between men and women in stroke risk factors and age at presentation, the goals of management should not necessarily be identical treatment for women and men, but rather optimal treatment for each individual patient based on his or her clinical status. Socioeconomic status is known to be associated with stroke incidence and outcomes, with several studies documenting an inverse association between socioeconomic status and stroke incidence, mortality, and case fatality rates (Cox et al., 2006; Jakovljevic et al., 2001; Kapral, Wang, Mamdani, & Tu, 2002; Kleindorfer et al., 2006). It is not known whether the inverse association between socioeconomic status and mortality is due to differences in access to care or to differences in comorbid illness or other risk factors. We found no association between income quintile and any of the stroke quality indicators evaluated. In 2000, the province of Ontario developed a strategy of coordinated and regionalized stroke care delivery, now known as the Ontario Stroke System (Heart and Stroke Foundation of Canada, 2000). The Ontario Stroke System includes the establishment of regional steering committees with a mandate to ensure optimal stroke care across an entire region and regional and district stroke centers with stroke-specific resources and expertise. The activities of the Ontario Stroke System include dissemination of best practice guidelines, patient and provider education, and regular audits and feedback of stroke care delivery through detailed chart audits (Lewis et al., 2006). It is
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likely that this coordinated stroke system has helped to minimize disparities in stroke management and outcomes based on gender, region, and socioeconomic status. Some study limitations deserve comment. We analyzed data from a hospital-based cohort, and thus do not have information on potential gender differences in the care of patients who do not seek hospital attention for stroke syndromes or for those who receive ambulatory care for primary and secondary stroke prevention. However, it should be emphasized that in contrast with most studies based on medical records review, our study sample included not only hospitalized patients, but also those seen in the emergency department but not admitted to hospital. Although we stratified our analyses by age and neighborhood income, we were unable to study other potential social determinants of care and outcomes such as recent immigrancy, race/ ethnicity, and education. In addition, we focused on the quality of acute stroke care delivery, rather than on rehabilitation or reintegration. Previous research has found that women are more likely than men to experience poor functional outcomes, incomplete recovery, and depression after stroke, and our study does not provide data on these important outcome measures (Chong, Lee, Boden-Albala, Paik, & Sacco, 2006; Di Carlo et al., 2003; Glader et al., 2003; Kapral et al., 2005). Our data collection through chart review rather than direct patient interviews and assessments may have led to underestimates of the prevalence of some risk factors such as smoking and hypertension. In addition, we were unable to obtain information on important factors such as body mass index and counseling for smoking cessation. However, chart review is likely to provide valid results for inhospital interventions such as thrombolysis, stroke unit care, and consultations, and our data source is strengthened by the inclusion of important prognostic variables, such as stroke severity, which are not routinely available in administrative databases or other registries. Finally, some patients, particularly those in the oldest age groups, may not receive recommended stroke care interventions because of legitimate contraindications, and we did not address this in our analyses. In conclusion, in this province-wide study, we found lower rates of carotid imaging, carotid endarterectomy, and lipidlowering therapy in women compared with men. These results are consistent with those of multiple previous studies in the area of cardiovascular disease, and deserve further evaluation to determine the root causes and possible solutions. However, we found that most other aspects of stroke care and outcomes were similar for women and men. This somewhat unexpected finding may be in part explained by the presence of an organized provincial stroke care strategy.
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Author Descriptions Dr. Kapral is an internist and health services researcher in the area of stroke in women.
Drs. Degani and Hall are epidemiologists with expertise in health services research and cardiovascular disease.
Dr. Fang is a biostatistican.
Drs. Silver and Saposnik are stroke neurologists and researchers.
Ms. Robertson and Ms. Richards are research nurses with expertise in cardiovascular disease.
Dr. Bierman, principal investigator of the POWER Study, is OWHC Chair in Women’s Health and Associate Professor, Bloomberg Faculty of Nursing; Health Policy, Evaluation, and Management; and Medicine, University of Toronto; and Scientist, Li Ka Shing Knowledge Institute, St. Michael's Hospital.