QUANTITATIVE RESEARCH
Avoidable Mortality for Causes Amenable to Medical Care, by Occupation in Canada, 1991-2001 Cameron A. Mustard, ScD,1,2 Amber Bielecky, MSc,1 Jacob Etches, PhD,1 Russell Wilkins, MUrb,3,4 Michael Tjepkema, MPH,4 Benjamin C. Amick, PhD,1,5 Peter M. Smith, PhD,1,2 Kristan J. Aronson, PhD6
ABSTRACT Objective: To describe the incidence of avoidable mortality for causes amenable to medical care among occupation groups in Canada. Method: A cohort study over an 11-year period among a representative 15% sample of the non-institutionalized population of Canada aged 30-69 at cohort inception. Age-standardized mortality rates for causes amenable to medical care and all other causes of death were calculated for occupationallyactive men and women in five categories of skill level and 80 specific occupational groups as well as for persons not occupationally active. Results: Age-standardized mortality rates per 100,000 person-years at risk for causes amenable to medical care and for all other causes were 132.3 and 218.6, respectively, for occupationally-active women, and 216.6 and 449.3 for occupationally-active men. For causes amenable to medical care and for all other causes, for both sexes, there was a gradient in mortality relative to the five-level ranking by occupational skill level, but the gradient was less strong for women than for men. Across the 80 occupation minor groups, for both men and women, there was a linear relationship between the rates for causes amenable to medical care and the rates for all other causes. Conclusions: For occupationally-active adults, this study found similar gradients in mortality for causes amenable to medical care and for all other causes of mortality over the period 1991-2001. Avoidable mortality is a valuable indicator of population health, providing information on outcomes pertinent to the organization and delivery of health care services. Key words: Occupations; cause of death; health services research La traduction du résumé se trouve à la fin de l’article.
T
he specific contribution of health care in reducing socioeconomic health inequalities continues to be an important policy focus in the funding, organization and delivery of health care in Canada. Arising from this policy focus, the monitoring of socio-economic equity in access to health services and the quality of health services is an important research priority.1-5 The concept of avoidable mortality has been applied in mortality surveillance studies to identify geographic or temporal differences in cause-specific mortality which is amenable to primary or secondary prevention.2,6-13 When the definition of avoidable mortality is restricted to those causes of death which can be prevented by timely access to medical care, approximately 30% of population mortality is defined as avoidable and this proportion is higher in working-age adults.13 Relatively few studies have reported on socio-economic differences in avoidable mortality. A recent report examined changes in avoidable mortality in urban Canada over the 25-year period 19711996 following the introduction of universal health insurance for medically necessary services.2 For deaths before age 75, differences between the richest and poorest 20% of the urban population in age-standardized expected years of life lost due to deaths amenable to medical care decreased 60% for men and 78% for women. The decrease in income-related disparities due to non-amenable causes was much smaller (15% for men and 9% for women). The surveillance and monitoring of population health trends in most countries includes the use of large, nationally-representative
500 REVUE CANADIENNE DE SANTÉ PUBLIQUE • VOL. 101, NO. 6
Can J Public Health 2010;101(6):500-6.
population-based cohort studies of mortality, usually formed by linking records for national census respondents to vital statistics death registrations.14-18 Until recently, no nationally-representative census-based cohort had been established in Canada. To address this limitation, Statistics Canada, the Institute for Work & Health and the Direction de la Santé Publique de Montréal-Centre collaborated in the creation of a database (the 1991-2001 Canadian census mortality follow-up study) linking a 15% sample of 1991 census respondents to the Canadian Mortality Data Base.1 The objective of this study was to examine differences in the incidence of avoidable mortality for causes amenable to medical care among occupationally-active adults in Canada aged 30-69 by occupation and skill level as well as for persons who were not occupationally active. Occupation and skill level were used to estimate socio-economic differences in mortality amenable to medical care.
Author Affiliations 1. Institute for Work & Health, Toronto, ON 2. Dalla Lana School of Public Health, University of Toronto, Toronto, ON 3. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON 4. Health Analysis Division, Statistics Canada, Ottawa, ON 5. School of Public Health, University of Texas, Houston, Texas 6. Department of Community Health and Epidemiology, Queen’s University, Kingston, ON Correspondence: Cameron Mustard, Institute for Work & Health, 481 University Ave, Suite 800, Toronto, ON M5G 2E9, Tel: 416-927-2027, ext. 2143, E-mail:
[email protected] Conflict of Interest: None to declare.
© Canadian Public Health Association, 2010. All rights reserved.
AVOIDABLE MORTALITY BY OCCUPATION IN CANADA
Table 1.
Avoidable Mortality for Causes Amenable to Medical Care and for All Other Causes, by Occupational Skill Level, Non-institutionalized Persons Aged 30-69 at Cohort Inception, Canada, 1991-2001 Occupational Skill Level
Number of Deaths
Personyears at Risk
Crude Mortality Rate
ASMR
95% Confidence Interval
SRR
95% Confidence Interval
987 529 2025 2981 1073
1,395,200 585,420 2,222,070 3,040,850 860,830
70.7 90.4 91.1 98.0 124.6
108.3 140.1 129.8 135.2 151.2
99.1-118.3 125.2-156.7 123.2-136.8 129.4-141.3 140.7-162.5
0.82 1.06 0.98 1.02 1.14
0.75-0.89 0.95-1.18 0.94-1.03 0.99-1.06 1.07-1.22 1.63-1.76
Women Causes amenable to medical care Professional Managerial Skilled/Technical/Supervisory Semi-skilled Unskilled
Men
No occupation
8637
2,679,240
322.4
223.9
218.5-229.5
1.69
All occupations (reference)
7595
8,104,380
93.7
132.3
128.7-136.1
1.00
All other causes of death Professional Managerial Skilled/Technical/Supervisory Semi-skilled Unskilled
1364 751 3137 4491 1661
1,395,200 585,420 2,222,060 3,040,850 860,830
97.8 128.3 141.2 147.7 193.0
176.4 211.0 217.7 222.9 261.0
162.8-191.1 191.7-232.3 208.6-227.1 214.8-231.3 245.9-277.1
0.81 0.96 1.00 1.02 1.19
0.75-0.87 0.88-1.06 0.96-1.03 0.99-1.05 1.13-1.26
No occupation
15,725
2,679,240
586.9
363.5
356.7-370.3
1.66
1.61-1.71
All occupations (reference)
11,404
8,104,380
140.7
218.6
213.6-223.8
1.00
1385 1989 5501 4665 2335
1,286,350 1,482,000 3,377,130 2,517,960 937,920
107.7 134.1 162.9 185.3 249.0
158.7 178.9 213.9 248.0 270.4
149.5-168.5 169.9-188.4 207.6-220.4 239.8-256.4 258.9-282.4
0.73 0.83 0.99 1.14 1.25
0.69-0.78 0.79-0.87 0.97-1.01 1.11-1.18 1.20-1.30 2.43-2.60
Causes amenable to medical care Professional Managerial Skilled/Technical/Supervisory Semi-skilled Unskilled No occupation
11,663
1,235,860
943.7
544.2
528.7-560.2
2.51
All occupations (reference)
15,875
9,602,360
165.3
216.6
212.8-220.4
1.00
All other causes of death Professional Managerial Skilled/Technical/Supervisory Semi-skilled Unskilled
2938 4020 11,197 9124 4548
1,286,350 1,483,000 3,377,130 2,517,960 937,920
228.4 271.1 331.6 362.4 484.9
343.0 386.8 444.3 500.0 557.0
328.9-357.6 372.6-401.5 434.9-453.8 487.8-512.5 539.7-574.9
0.76 0.86 0.99 1.11 1.24
0.73-0.79 0.83-0.89 0.97-1.01 1.09-1.14 1.20-1.28
No occupation
22,694
1,235,860
1836.3
972.6
951-994.6
2.16
2.11-2.22
All occupations (reference)
31,827
9,602,360
331.4
449.3
443.6-455
1.00
ASMR: Age-standardized mortality rate, SRR: Standardized rate ratio. Bold font in SRR column indicates statistically significant (p
