Socio-economic gradients in the occurrence of stroke and 30 days in-hospital mortality after a stroke in Canada

2014 Canadian Population Health Association Conference

Toronto, Canada

Z. Chaudhary, K. Nguyen, L. Yin, C. Tosevski, Y. Gurevich

Canadian Institute for Health Information

2

Overview

• Introduction– Why Stroke?– Indicators (Stroke Event and 30-Day

Stroke In-hospital Mortality)• SES lens• Results• Concluding remarks• Resources

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Why Stroke?

Stroke

Among top 10 causes

of in-hospital mortality

Common cause of hospitalization

Cost

4

Stroke Indicators

• Stroke Event Rate Age-standardized rate of new stroke events admitted to an acute care hospital, per

100,000 population age 20 and older

• 30-Day Stroke In-Hospital Mortality The risk-adjusted rate of all-cause in-

hospital deaths occurring within 30 days of first admission to an acute care hospital with a diagnosis of stroke

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General Methodology

Data Source - Discharge Abstract Database (DAD)• Acute care hospitalization data from all

provinces/territories except Quebec

• Rates for Quebec are not available due to differences in data collection

Level of Reporting - based on patient postal code of residence

• Canada

• Provinces/territories

• Regions

6

SES Lens

Social stratification and income distribution have an impact on population health and safety

Measuring and reporting health disparities are important because some of them may be reduced or prevented

Understanding Stroke in the socio-economic context could help to focus on areas where interventions are more needed

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SES Lens (cont’d)

• Neighbourhood Income Quintile - used as a proxy for SES (Quintile 1 – least affluent, Quintile 5 - most affluent)

• Disparity Rate RatioRatio of the rate of a health indicator for the least affluent neighbourhood income quintile to the rate for the most affluent neighbourhood income quintile

• Potential Rate Reduction Potential reduction in a health indicator rate that

would occur in the hypothetical scenario that each socio-economic group in the jurisdiction experienced the rate of the most affluent socio- economic group

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Hospitalized Stroke Events Rate - National Trend

2006 2007 2008 2009 2010 2011 2012 201395

100

105

110

115

120

125

130

135

140

145

150

155

160

111109

106105 103

99

152150

146 146

141 139

130128

124 124121

118

Combined

Male

Female

Year

Age

-Sta

ndar

dize

d H

ospi

taliz

ed E

vent

Stro

ke R

ate

(per

100

,000

)

*Age-Standardized Rates exclude Quebec

↓ 9%

↓ 9%

↓ 11%

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Hospitalized Stroke Event Rate - Provincial Variation FY2007-2008 & FY2012-2013

NL PE NS NB ON MB SK AB BC0

20

40

60

80

100

120

140

160

180

FY07FY12

Province

Age

-Sta

ndar

dize

d R

ate

per 1

00,0

00 P

opul

atio

n

130118

10

Stroke Event Rate - by SES FY 2007-2008 & FY 2012-2013

Q1 Q2 Q3 Q4 Q50

20

40

60

80

100

120

140

160

180

154

137129 124

116

138

125 123115

109

FY07FY12

Neighbourhood Income Quintile

Age

-sta

ndar

dize

d ra

te (p

er 1

00,0

00)

11

Stroke Event Rate - by SES and GenderFY 2012-2013

1-Least Affluent 2 3 4 5-Most Affluent0

20

40

60

80

100

120

140

160

180166

150 148

135129

116

103 10397

92

MaleFemale

Neighbourhood Income Quintile

Age

-Sta

ndar

dize

d R

ate

per 1

00,0

00 P

opul

atio

n

12

Hospitalized Stroke Rates - by SES & ProvinceFY 2012-2013

CA NL PE NS NB ON MB SK AB BC0

20

40

60

80

100

120

140

160

180

200

1-Least Affluent 2 3 4

5-Most Affluent

Age

-Sta

ndar

dize

d R

ate

per 1

00,0

00 P

opul

atio

n

PRR-11% ↓

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30-Day Stroke In-hospital Mortality National Trend

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 20110

5

10

15

20

25

19.2 18.9 18.7 18.6 18.9 19.118.3 18.2 18.0 17.7

16.916.0

15.0 14.3

Year

Ris

k-A

djus

ted

Rat

e (%

)

↓ 26%

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30-day In-hospital Stroke Mortality Provincial Variation, 2009 & 2011

NL PE NS NB ON MB SK AB BC0

5

10

15

20

25FY09

Province

Ris

k-A

djus

ted

Rat

e (p

er 1

00)

16.014.3

15

30-day In-hospital Stroke Mortality - by SES2009 & 2011

Q1 Q2 Q3 Q4 Q50

2

4

6

8

10

12

14

16

1816.9

16.015.4 15.6 15.8

14.1 13.9 13.813.1 13.1

FY09FY11

Neighbourhood Income Quintile

Risk

-Adj

uste

d Ra

ter(%

)

PRR-4%↓

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Concluding Remarks

• Hospitalizations for stroke present a consistent association with socio-economic status.

• However once the patients are admitted to hospital difference in stroke mortality rates by socio-economic status are much less

• Examining trends and variations could help jurisdictions identify areas for improvement

• Could be used to target efforts needed to close sex and socio-economic gaps

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Resources

• OurHealthSystem.ca website– Indicator results at national, provincial/territorial and health region

level

www.OurHealthSystem.ca

• Health Indicators e-publication– Indicator results at national, provincial

/territorial and health region level

www.cihi.ca/hirpt

• Indicator Library– http://indicatorlibrary.cihi.ca

Questions?

Zeerak ChaudharyProject Lead, Health Indicators & Client Support,Canadian Institute for Health Information (CIHI)

Email: zchaudhary@cihi.ca

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Thank You!