Examining%20the%20Socioeconomic%20Gradient%20in%20Health-Related%20Quality%20of%20Life%20in%20Canada

1
Examining the Socioeconomic Gradient in
Health-Related Quality of Life in Canada

• Cameron N. McIntosh
• and Philippe Finès
• Health Information and Research Division
• Statistics Canada, Ottawa

2
Context and Background

• Despite the fundamental principle of health for
  all, socioeconomic disparities in health persist
  in Canada (e.g., Choinière, Lafontaine,
  Edwards, 2000 Raphael, 2000 Wilkins, Tjepkema,
  Choinière, Mustard, forthcoming)
• Many health indicators exhibit a socioeconomic
  gradient
• Overall/cause-specific mortality
• Risk factors
• Incidence/prevalence rates for chronic disease
• Self-perceived health

3
Health-Related Quality of Life

• The value attached to the duration of life as
  modified by the impairments, functional states,
  perceptions, and social opportunities that are
  influenced by disease, injury, treatment or
  policy (Patrick Erickson, 1993)

4
Rationale

• Overall socioeconomic disparities in
  health-related quality of life well studied at
  the national level in Canada (e.g., Eng Feeny,
  2007)
• Condition-specific disparities mainly studied
  sub-nationally, using small clinical samples
  (e.g., Marra et al., 2004)

5
Objectives

• Quantify differences in health-related quality of
  life between socioeconomic strata, both generally
  and for specific health conditions in a
  representative sample of the household population
• Identify areas where interventions directed at
  reducing disparities might produce the greatest
  health benefits

6
Data Source

• 2000-2001 Canadian Community Health Survey (CCHS)
• Cross-sectional survey that collects information
  on health status, health determinants, and health
  care utilization
• representative of the Canadian household
  population aged 12 and over
• 131,535 person records in cycle 1.1
• Only cycle with HUI3 administered to all
  respondents

7
Analysis Variables

• Income adequacy
• respondents best estimates of total household
  income divided by adjusted household size, and
  then partitioned into deciles
• Educational attainment
• Less than high school
• High school graduation, including trades
  qualification
• Post-secondary certificate or diploma
• University degree (BA or higher)

8
Analysis Variables

• Selected Chronic Conditions
• Conditions that have lasted or are expected to
  last six months or more and have been diagnosed
  by a health professional.
• Four high impact conditions cancer, heart
  disease, diabetes, and arthritis

9
Health-Related Quality of Life Health Utilities
Index Mark 3

• Health-related quality of life measured by the
  Health Utilities Index Mark 3 (HUI3)
• HUI3 assesses levels of functioning on eight
  attributes of health status Vision, Hearing,
  Speech, Ambulation, Dexterity, Emotion,
  Cognition, and Pain.
• HUI3 score
• -0.36 0.0 1.0
• (worst possible DEAD (best
  possible
• health state)
  health state)

10
Methods

• For the overall population and then for each
  chronic condition subpopulation
• Sex-specific mean global HUI3 scores and 95
  confidence intervals computed for income and
  education categories, by 10-year age group
• Used survey sampling weights and the bootstrap
  technique to account for the complex survey
  design

11
Figure 1 Mean HUI3 For Poorest and Richest
Deciles by 10-year Age Goup, Males
1.00
?0.09
0.90
?0.12
?0.14
?0.20
?0.17
0.80
?0.15
0.70
0.60
D1 (Poorest)
D10 (Richest)
Mean HUI3
0.50
0.40
0.30
0.20
0.10
0.00
20
30
40
50
60
70
80
Age Group
12
Figure 2 Mean HUI3 For Poorest and Richest
Deciles by 10-year Age Group, Females
1.00
?0.08
0.90
?0.12
?0.13
?0.14
0.80
?0.12
0.70
?0.08
0.60
D1 (Poorest)
Mean HUI3
D10 (Richest)
0.50
0.40
0.30
0.20
0.10
0.00
20
30
40
50
60
70
80
Age Group
13
Figure 3 Mean HUI3 for Most and Least
Well-Educated Males, by 10-Year Age Group
1.00
?0.08
0.90
?0.10
?0.07
?0.10
?0.09
0.80
?0.08
0.70
Less than high school
Bachelors degree or higher
0.60
0.50
Mean HUI3
0.40
0.30
0.20
0.10
0.00
20
30
40
50
60
70
80
Age Group
14
Figure 4 Mean HUI3 for Most and Least
Well-Educated Females, by 10-Year Age Group
1.00
?0.11
0.90
?0.10
?0.10
?0.07
?0.08
0.80
0.70
Less than high school
?0.03
Bachelors degree or higher
0.60
Mean HUI3
0.50
0.40
0.30
0.20
0.10
0.00
20
30
40
50
60
70
80
Age Group
15
Table 1 Mean HUI3 for Richest and Poorest
Deciles, Men Aged 75 With Selected Chronic
Conditions
Income Decile Total Population (Men aged 75) Chronic Condition Subgroup Chronic Condition Subgroup Chronic Condition Subgroup Chronic Condition Subgroup
Cancer Heart Disease Diabetes Arthritis
D10 (Richest) 0.815 0.780 0.832 0.807 0.746
D1 (Poorest) 0.662 0.578 0.658 0.637 0.638
? 0.153 0.202 0.174 0.170 0.108
Data Source 2000 2001 Canadian Community Health Survey. Data Source 2000 2001 Canadian Community Health Survey. Data Source 2000 2001 Canadian Community Health Survey. Data Source 2000 2001 Canadian Community Health Survey. Data Source 2000 2001 Canadian Community Health Survey. Data Source 2000 2001 Canadian Community Health Survey.
16
Table 2 Mean HUI3 for Most and Least
Well-Educated Males, Aged 75 with Selected
Chronic Conditions
Educational Level Total Population (Men aged 75) Chronic Condition Subgroup Chronic Condition Subgroup Chronic Condition Subgroup Chronic Condition Subgroup
Cancer Heart Disease Diabetes Arthritis
E4 (Bachelors degree or higher) 0.788 0.775 0.764 0.836 0.741
E1 (Less than high school) 0.709 0.586 0.639 0.628 0.623
? 0.079 0.189 0.125 0.208 0.118
Data Source 2000 2001 Canadian Community Health Survey. Data Source 2000 2001 Canadian Community Health Survey. Data Source 2000 2001 Canadian Community Health Survey. Data Source 2000 2001 Canadian Community Health Survey. Data Source 2000 2001 Canadian Community Health Survey. Data Source 2000 2001 Canadian Community Health Survey.
17
Limitations

• Causality should not be inferred between
  socioeconomic status (SES) and health-related
  quality of life
• Potential self-report bias on CCHS
• Income concept broadly defined (based on total
  household income)
• Limited to household population (institutional
  residents excluded)

18
Discussion

• Robust socioeconomic disparities in
  health-related quality of life exist in Canada
• Magnitude of these disparities often differs by
  age, sex, definition of SES, and health condition
  
• Interventions directed at reducing disparities in
  health-related quality of life could produce
  substantial gains at the population level

19
Discussion

• Within chronic condition subgroups, why do
  persons of higher SES have better health-related
  quality of life than lower SES persons? Possibly
  due to
• Higher pre-condition health status
• Better condition management
• Better physical and social environments
• Further investigation is required to disentangle
  the potential reasons
• Demonstrates importance of SES for burden of
  disease studies and cost-effectiveness analysis
  of treatments

20
Future Directions

• Integrate mortality and health-related quality of
  life data to provide a more complete picture of
  socioeconomic differentials in health (e.g.,
  Wolfson, McIntosh, Finès, Wilkins, forthcoming)
• Use a broader range of income concepts to define
  SES (e.g., personal earnings versus total
  household income)
• Examine socioeconomic differentials in
  health-related quality of life for other health
  conditions
• Investigate the pathways through which SES
  produces different health outcomes

21
References

• Choinière R, Lafontaine P, Edwards AC.
  Distribution of cardiovascular disease risk
  factors by socioeconomic status among Canadian
  adults. CMAJ 2000 162 (9 Suppl) S13-S24.
• Eng K, Feeny D. Comparing the health of low
  income and less well educated groups in the
  United States and Canada. Population Health
  Metrics 2007 5 10.
• Feeny D, Furlong W, Torrance GW, Goldsmith CH,
  Zhu Z, DePauw S, Denton M, Boyle M.
  Multiattribute and single-attribute utility
  functions for the Health Utilities Index Mark 3
  system. Med Care 200240(2)113-28.

22
References

• Marra CA, Lynd LD, Esdaile JM, Kopec J, Anis AH.
  The impact of low family income on self-reported
  health outcomes in patients care environment.
  Rheumatology 2004431390-1397.
• Patrick DL, Erickson P. Health Status and Health
  Policy quality of life in health care evaluation
  and resource allocation. New York Oxford
  University Press 1993.
• Raphael D. Health inequalities in Canada current
  discourses and implications for public action.
  Critical Public Health 200010(2)193-216

23
References

• Wilkins R, Tjepkema M, Choinière R, Mustard C.
  The 1991 census mortality follow-up study Cohort
  mortality by individual, family, household and
  neighbourhood characteristics, based on a 15
  sample of the Canadian adult population. Health
  Reports (forthcoming).
• Wolfson MC, McIntosh CN, Finès P, Wilkins R.
  Refining the measurement of health inequalities
  in Canada new data, new approaches. Paper to be
  presented at the 30th General Conference of the
  International Association for Research in Income
  and Wealth, Portoroz, Slovenia, August 24-30,
  2008.

24
Acknowledgements

• The guidance and feedback of Russell Wilkins and
• Michael Wolfson are gratefully acknowledged.

25
Contact Information

• Cameron N. McIntosh
• Analyst
• Health Information and Research Division
• 24-L R.H. Coats Building
• Statistics Canada 100 Tunney's Pasture Driveway
• Government of Canada
• Ottawa, Ontario K1A 0T6
• phone [phone] fax [phone]
• email cameron.mcintosh_at_statcan.ca