Measuring health care inequalities using the Census- DAD data linkage

Transcription

1 Measuring health care inequalities using the Census- DAD data linkage Erin Pichora, Program Lead Canadian Population Health Initiative Canadian Institute for Health Information November 14, 2017

2 Overview CIHI s Equity Program of Work Defining Stratifiers for Measuring Health Inequalities Equity in Health Care Project using Linked Data Key Findings Income stratifier Education stratifier Summary and Next Steps 2

3 CIHI s Equity Program of Work Advancing the measurement of health inequalities 1. Develop standards 2. Produce actionable analysis 3. Build capacity Reports planned for release in Defining Stratifiers for Measuring Health Inequalities - report - Inequalities in Asthma Hospitalizations among Children and Youth - chart book - Equity Toolkit: Guide for Measuring Health Inequalities 3

4 Equity Program of Work: Collaborating and leveraging partnerships 4

5 Building on previous health inequalities reporting at CIHI 2015 Trends in Income-related Health Inequalities Project 2016 Pan-Canadian Dialogue to Advance the Measurement of Equity in Health Care 5

6 Equity in Health Care Project using Linked Data - a CIHI and Statistics Canada collaboration Objective 1: Inform development of common definitions of equity stratifiers for measuring health inequalities Objective 2: Expand the measurement of health inequalities using 3 hospitalization indicators AMI (age 20+) Sources Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). Rotermann M, et al. Linking 2006 Census and hospital data in Canada. Health Reports

7 Linkage DAD to 2006 long-form census Long-form ~ 20% of Canadian population (higher in Territories) 94% of these respondents were eligible for linkage 17% of eligible DAD cases linked to long-form varying from 16% in NL and 63-69% in Nunavut Estimates from linked cohort weighted to ~ 80% of population Source Rotermann M, et al. Linking 2006 Census and hospital data in Canada. Health Reports

8 How does the coverage vary by indicator? Lower for asthma and COPD mostly due to babies born after census day Asthma <75 years ( ) Indicator COPD <75 years ( ) AMI 20+ years ( ) Full DAD cases 34,305 74, ,018 Linked DAD-Census long-form cases (weighted counts) 22,830 56,945 82,595 % of full DAD 67% 77% 80% Source Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD) CIHI. Discharge Abstract Database 8

9 Indicator selection and rate calculation Indicators: Calculation: Ambulatory care sensitive conditions (<75 yrs): - Asthma - COPD - Years: Heart attack hospitalizations (>20 yrs) - Years: Numerator: sum of all hospitalizations (pooled years) Denominator: weighted person counts from 2006 Census long-form population with: 1) Population ageing approach for 2007, 2008 (COPD and asthma hospitalizations) 2) Doubling of denominator (heart attack hospitalizations) Direct age-standardization to 2011 population 9

10 Ageing denominator Asthma & COPD hospitalizations for 0-74 years Census Data Collection, May 2006 Children born on or after May 2006 are not included in the DAD-Census linkage < 1 year as of April 1 aged out of denominator (1-74 years) 10 < 2 years as of April 1 st aged out of denominator (2-74 years)

11 Hospitalization rate per 100,000 (age-standardized) Hospitalization rates lower for linked cohort than full DAD (for all indicators) Full DAD Linked Cohort Asthma COPD AMI Indicator Sources Discharge Abstract Database, Canadian Institute for Health Information. Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). 11

12 Developing common definitions: Key activities Environmental scan and working group Equity in health care project using linked data Stratifiers: Age, Sex, Gender, Education, Income, Geographic Location and Racial identity 12

13 Income Stratifier 13

14 Income stratifier definition: Key recommendations Relative income using income quintiles Income quintiles should be derived at the appropriate geographic level using an appropriate income measure. Should be adjusted for the number of people in the household Can be derived based on before- or after-tax data; however, it is good practice to report which type of data you are using to measure inequalities Individual-level and area-level income quintiles provide complementary information when measuring health inequalities, where possible both should be used 14

15 Results from the linkage analysis allow us to make the following 3 comparisons 1. Before tax vs after tax 2. Individual-level vs area-level 3. Linked cohort vs full DAD 15

16 Comparison 1: Individual-level income quintiles before vs. after tax Household income, before tax More commonly available and is used for quintiles in both CCHS and PCCF+ Household income, after tax Captures the funds available to a household, family or individual for consumption, savings and investment (From Statistics Canada) 16

17 Hospitalization Rate per 100,000 (Age-Standardized) Comparison 1: Inequalities similar using quintiles based on before-tax or after-tax COPD hospitalizations by income quintile, <75 years, Canada (excluding Quebec), (pooled) Before-Tax Rate Ratio : 5.0 Rate Difference : 154 per 100,000 After-Tax Rate Ratio : 4.7 Rate Difference : 147 per 100, Before-Tax After-Tax Source Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). Q1 (lowest) Q2 Q3 Q4 Q5 (highest) Income Quintile 17

18 Rate per 100,000 (age-standardized) Comparison 2: Inequalities larger using individual-level vs area-level - COPD 250 COPD hospitalizations by income quintile, <75 years, Canada (excluding Quebec), (pooled) Area-level RR: 3.8 RD: 126 per 100,000 Individual-level RR: 5.0 RD: 154 per 100, Area-level Individual-level Q1 (lowest) Q2 Q3 Q4 Q5 (highest) Income quintile Source Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). 18

19 Rate per 100,000 (age-standardized) Comparison 2: Inequalities similar using individual-level vs area-level - AMI AMI hospitalizations by income quintile, 20+ years, Canada (excluding Quebec), (pooled) Area-level RR: 1.4 RD: 89 per 100,000 Individual-level RR: 1.4 RD: 89 per 100, Area-level 100 Individual-level 50 0 Q1 (lowest) Q2 Q3 Q4 Q5 (highest) Source Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). Income quintile 19

20 Rate per 100,000 (age-standardized) Comparison 2: Inequalities similar using individual-level vs area-level - asthma Asthma hospitalizations by income quintile, 0-19 years, Canada (excluding Quebec), (pooled) Area-level RR: 1.5 RD: 40 per 100,000 Individual-level RR: 1.7 RD: 46 per 100, Area-level Individual-level 20 0 Q1 (lowest) Q2 Q3 Q4 Q5 (highest) Income quintile Source Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). 20

21 Rate per 100,000 (age-standardized) Comparison 3: Area-level income-related health inequalities similar - full DAD vs linked cohort Asthma hospitalizations by area-level income quintile, 0-19 years, Canada (excluding Quebec), (pooled) Linked Cohort RR: 1.5 RD: 40 per 100, Full DAD RR: 1.6 RD: 58 per 100, Linked 60 DAD Q1 (lowest) Q2 Q3 Q4 Q5 (highest) Income Quintile Sources Discharge Abstract Database, Canadian Institute for Health Information. Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). 21

22 Key Findings: Income-related inequalities Large income-related inequalities for all 3 indicators Inequalities are similar using after tax vs. before tax (individual-level) For some indicators, individual-level income data showed larger inequalities than using area-level income COPD hospitalization among those less than 75 years Inequalities are similar using the linked cohort vs. full DAD (area-level) 22

23 Education Stratifier 23

24 Education stratifier definition: Key recommendations Educational attainment measured using a multi-category (4-5 categories) approach Household-level is recommended over individual-level Inequalities are similar at the household-level and at the individual-level 24

25 Proportion of population by household educational attainment 25

26 Multi-category versus dichotomous Asthma hospitalizations for children and youth by household education Source Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). 26

27 Rate per 100,000 (age-standardized) Large education-related inequalities COPD hospitalization COPD hospitalizations by education, <75 years, Canada (excluding Quebec), (pooled) 217 Rate ratio: 9.5 Rate difference: 194 per 100, Less than high school High school Post secondary school below bachelors Source Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). Highest household educational attainment 27 Bachelors degree Above bachelors degree

28 Rate per 100,000 (age-standardized) Large education-related inequalities - AMI 400 AMI hospitalizations by education, >20 years, Canada (excluding Quebec), (pooled) Rate ratio: 1.9 Rate difference: 160 per 100, Less than high school High school Post secondary school below bachelors Source Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). Highest household educational attainment 28 Bachelors degree Above bachelors degree

29 Rat per 100,000 (age-standardized) Large education-related inequalities, especially among boys asthma < 20 years Asthma Hospitalizations, 0-19 years, Canada (excluding Quebec), (pooled) Boys Rate ratio: 2.6 Rate difference: 111 per 100,000 Girls Rate ratio: 1.8 Rate difference: 41 per 100, Boys Girls Less than high school High school Post secondary school below bachelors Source Statistics Canada. 2006/2007 to 2008/2009 census-linked Discharge Abstract Database (DAD). Highest household educational attainment 29 Bachelors degree Above bachelors degree

30 Key Findings: Education-related inequalities Striking inequalities in COPD, AMI and asthma hospitalizations by household education Greater inequalities observed using a multi-category approach Education-related inequalities in asthma hospitalization Greater for boys than for girls 30

31 Summary Linking administrative health and social data has the potential to expand the measurement of health inequalities in Canada DAD linked to 2006 long-form census available in RDC Individual-level approach and area-level analysis complementary for examining income-related inequalities; varies by indicator New! Education data reveal striking gradient of education-related inequalities for 3 hospitalization indicators, with interaction with sex for asthma Limitations include timeliness of data and challenges of measuring inequalities at a more local level due to sample size 31

32 Next Steps Defining Stratifiers for Measuring Health Inequalities report (March 2018) Age, Sex, Gender, Education, Income, Geographic Location and Racial identity Working definition document available upon request Inequalities in Asthma Hospitalization in Children and Youth chart book (March 2018) Equity Toolkit: A guide to measuring health inequalities in Canada (Spring 2018) 32

33 Acknowledgements Co-authors, CIHI Sara Allin Harshani Dabere Jean Harvey Stephanie Ko Sarah Roberts Larry Shaver Co-authors, Statistics Canada Philippe Finès Claudia Sanmartin 33

34 @cihi_icis cihi.ca