Tracking Disparity: Trends in ethnic and socio-economic inequalities in mortality, 1981 - 2004

1. Tracking Disparity: Trends in ethnic and socio-economic inequalities in mortality, 1981 - 2004 Professor Tony Blakely, ASBHM 2008 Martin Tobias, June Atkinson, Li-Chia Yeh, Ken Huang.

2. Overview • Some background on NZCMS • Part I: Ethnic results • Part II: Socio-economic results • Part III: Contribution of socioeconomic position to ethnic inequalities • Part IV: Contribution of “behaviour” to ethnic and socio-economic inequalities trends in mortality: • Behaviour of society, institutions and governments - structural • Behaviour of health services • Behaviour of individuals – tobacco (diet, PA) • Discriminatory behaviour – racism There will be audience participation! Keen to have your questions/challenges during, and comments at end (eg, other behavioural data from NZ, Australian comparisons)

3. www.wnmeds.ac.nz/nzcms-info.html

4. Main sources for this presentation • Blakely T, Tobias M, Atkinson J, Yeh L-C, Huang K. Tracking Disparity: Trends in ethnic and socioeconomic inequalities in mortality, 1981-2004. Wellington: Ministry of Health, 2007. • Blakely T, Tobias M, Robson B, Ajwani S, Bonne M, Woodward A. Widening ethnic mortality disparities in New Zealand 1981-99. Soc Sci Med 2005;61(10):2233-2251. • Blakely T, Fawcett J, Hunt D, Wilson N. What is the contribution of smoking and socioeconomic position to ethnic inequalities in mortality in New Zealand? The Lancet 2006;368(9529):44-52. • Blakely T, Tobias M, Atkinson J. Inequalities in mortality during and after restructuring of the New Zealand economy: repeated cohort studies, 2008:BMJ.39455.596181.25. (Appearing in hardcopy 16 Feb.)

5. NZCMS: method in one slide 1991 census cohort (0-74 yr olds) Anonymous and probabilistic record linkage Deaths - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ———————————————————— - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ———————————————————— - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ———————————————————— - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ———————————————————— - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ————————————————————

6. Method to calculate mortality rates • Calculate rates directly off linked NZCMS data, using census ethnicity and income and standard cohort methods • Ages 1-74, age-standardised to WHO world population • Each of five ‘periods’ (ie, 1981-84, … 2001-04) are three years in duration – not full five-year intercensal • What has NZCMS added to New Zealand information? • Now have correct trends in mortality by ethnicity • Now have one of world’s largest cohort studies of smoking – active and passive • Rates by many socio-economic factors, with ability for multivariable analyses

7. Part I: Ethnic inequalities in mortality

8. All-cause mortality rates by ethnicity, 1-74 yrs

9. Absolute and relative measures of inequality Rate ratio = 2.37 Rate difference = 403 per 100,000

10. Ethnic disparities

12. Cardiovascular disease, 1-74 year olds combined • By what percentge has CVD mortality rates declined from 1981-84 to 2001-04: a) for European; b) for Māori? • 64% and 65% for male and female Europeans • 40% and 45% for male and female Māori

13. CVD mortality rates by ethnicity, 1-74 yrs

14. IHD mortality rates by ethnicity, 1-74 yrs

15. All-cancer mortality rates by ethnicity, 1-74 yrs

16. Lung cancer mortality rates by ethnicity

17. Colorectal cancer mortality rates by ethnicity

18. Colorectal cancer mortality rates: Decades of Disparity I

19. Breast cancer rates by ethnicity

20. Suicide rates by ethnicity, 1-74 yrs

21. Cause of death contributions to absolute inequality

23. Part II:Socio-economic inequalities in mortality

24. Ethnicity, socio-economic position and health Ethnicity SES Mortality

25. Method • Use NZCMS data: 81-84, 86-89, 91-94, 96-99, 01-04 • Treated equivalised (Jensen) household income as main socio-economic factor: • same fixed $ groups (ie, real 1996 dollars) • Calculate age- standardised mortality rates

26. Medium-high income cut-point (1996 real dollars) Low-medium income cut-point (1996 real dollars)

27. All-cause mortality rates by income • Mostly parallel tracking in absolute terms • 30% and 41% decreases for low and high income males, respectively • 27% and 37% decreases for low and high income females, respectively

28. Rate difference = 380 per 100,000 Rate ratio = 1.44 Rate difference = 379 per 100,00 Rate ratio = 1.72 Are inequalities increasing (81-84 to 96-99)? Answer: Absolutely not, relatively yes

29. Income disparities

31. Cardiovascular disease, 1-74 year olds

32. CVD mortality, 1-74 years: relative and absolute measures of inequality

33. All cancer, 1-74 year olds

34. Lung cancer, 1-74 year olds

35. Cause of death contributions to absolute inequality

36. Part III: Socio-economic mediation of ethnic inequalities in mortality

37. Audience question: how much of the gap in mortality rates is due to differences in socio-economic position?

38. Answering the question “What proportion (on average) of the Māori:European mortality inequality was mediated by socioeconomic position?” • Examine mortality rate trends cross-classified by ethnicity and income • Use regression analyses to adjust ethnic gaps in mortality for multiple socio-economic factors, labour force status and NZDep

39. All-cause mortality by ethnicity (Māori [black], European [orange]) by income

40. All-cause RR (Māori cf European), adjusting for socio-economic factors, PLM and NZDep

41. All-cause RR (Māori cf European), adjusting for socio-economic factors, PLM and NZDep

42. All-cause RR (Māori cf European), adjusting for socio-economic factors, PLM and NZDep

43. What proportion (on average) of the Māori:European mortality inequality was mediated by socioeconomic position? • At least half for working age adults, and about one third for older adults. • Small area deprivation contributed an extra 10%, over and above personal socio-economic factors. • For 25-59 year olds position in the labour market contributed 10% to 15%. • We have probably underestimated the contribution of socio-economic position in total (i.e. due to measurement error), BUT without doubt not all of ethnic inequalities in mortality are explained by socio-economic position.

44. Part IV: Contribution of “behaviour” to ethnic and socio-economic inequalities trends in mortality:- Behaviour of society, institutions and governments (structural)- Behaviour of health services- Behaviour of individuals – tobacco (diet, PA)- Discriminatory behaviour – racism

47. 1984 and all that …. • 1970s and early 1980s: • subsidies, regulated economy, low unemployment, etc.. • 1984 to 1993: • deregulation of the financial sector • reorganising the state sector • ending of state support for industry Resulting in: • flatter tax rates, targeted welfare, regressive consumption tax, market rentals, privatisation, user charges, widening income inequalities, etc… • health reform

48. Social determinants of health Hui Taumata 1984: ‘shock absorbers in the economy’

49. Unemployment rates by ethnicity (Social Report, MSD; Source: Statistics New Zealand, Household Labour Force Survey)