Dr George Disney, Dr Andrea Teng, June Atkinson, Frederieke Sanne van der Deen, Prof Nick Wilson, Prof Tony Blakely
In a study we just published, we found that whilst there have been declines in all-cause mortality rates, over time, for Māori, Pacific peoples and the European/Other ethnic group, there are still striking mortality gaps that need to be addressed.
Ethnic mortality inequalities are generally stable or even falling in absolute terms, but have increased on a relative scale. To further address these inequalities, NZ policy-makers have many options, ranging from equalising socio-economic factors between ethnic groups, improving access to health services, tobacco control and addressing the obesogenic environment.
Recently, especially in the United States, there has been a growing concern that social inequalities are increasingly leading to widening inequalities in health (1). Other recent research highlights the overall importance of inequalities to health, with a meta-analysis reporting that low socio-economic position was the third most important risk factor for premature mortality (2).
In our just published study (3), we update previous studies to include deaths from 2006-2011 and look at the changing ethnic inequalities in mortality rates in NZ over 30 years. We used cohort studies of the entire NZ population using probabilistically-linked census and mortality data from 1981 to 2011 (68.9 million person years of follow-up). All-cause mortality rates were highest for Māori, followed by Pacific peoples then European/Other. These rates declined in all three ethnic groups over time with Pacific peoples experiencing the slowest annual percentage fall in mortality rates, then Māori, with European/Other having the highest percentage falls (see the Figure below).
Note: You can check out all the data above, and make your own versions of such graphs and more using the NZCMS/CT Data Explorer.
Whilst falling mortality trends are always welcome, there are still wide mortality gaps between ethnic groups. While absolute inequalities, for both Māori and Pacific males compared to European/Other males have been falling since 1996, they still are excessive (see the first Figure below for the gap in rate differences). Also relative inequalities are increasing (see the second Figure below for the gap in the rate ratios).
For females, it was only Māori absolute inequalities (compared with European/Other) that have been falling. That is there were increasing absolute inequalities for Pacific females. In terms of the cause of death, cancer appeared to be becoming a more important contributor than cardiovascular disease (CVD) to absolute inequalities, with this especially so for Māori females.
Some favourable progress – but what can still be done?
While the decline in all-cause mortality rates for all ethnic groups in NZ is a favourable finding from a public health perspective, there is a need to accelerate progress on reducing absolute and relative health inequalities. There are many plausible ways that these inequalities could be further reduced – as we now detail.
Macro-economic and social policies
Previous research for this country has suggested that the widening in ethnic inequalities in health in the 1980s and 1990s was contributed to by structural economic changes to liberalise the market economy (4). Indeed, further risks for sustained inequalities may come if increased automation and other forces associated with globalisation result in increased unemployment and higher insecurity of employment among lower-skilled workers (5). We focus in this blog on areas most related to health interventions (see below), but note that interventions in the social policy domain that might help include: raising educational levels for Māori and Pacific peoples, increasing employment opportunities, increasing job security, higher tax credits for low-income families, and higher minimum wages. Indeed, we note the progress in the educational domain with the increases in the percentage of Māori and Pacific school leavers with school qualifications (6).
Addressing the obesogenic environment
As with many other high-income countries, a high body-mass index (BMI) is now the largest single cause of health loss overall in NZ (7). Obesity is a likely driver for inequalities from CVD, diabetes and some types of cancer for both Māori and Pacific peoples (given much higher burdens of overweight and obesity (8)). Indeed, detailed analysis of both cancer incidence and mortality by us (9) (see also this blog) has found that ethnic inequalities have actually widened most in the incidence of obesity-related cancers in NZ (particularly breast, endometrial and colorectal cancer). While the NZ Government is to be commended for adopting the idea of an obesity control strategy, the actual strategy is deficient in many ways. In particular, there is a need for interventions to address the obesogenic environment such as:
- Mandatory front-of-package health rating labelling of food
- Banning junk food marketing to children
- Following other jurisdictions (eg, Mexico, France and various US cities) with the introduction of taxes on sugary drinks.
For example, in Berkeley, California, a sugary drinks tax is working to reduce sales and consumption of these drinks (10,11), with water and milk sales increasing after the tax (11). If such measures were carefully designed and appropriately implemented in NZ, they could well contribute to reductions in inequalities. For example, there is some evidence for a greater reduction in sugary drinks consumption by lower socio-economic groups in Mexico after the new tax there (12). Also Berkeley’s excise tax on sugary drinks reduced consumption in low-income neighbourhoods (10).
Advancing tobacco control
The second most important risk factor causing health loss in NZ is tobacco smoking (7). Our results for ethnic inequalities in lung cancer (and also for CVD, and other cancers) reflect the marked ethnic gradient in smoking in this country: both currently and as projected into the future (13). Achieving a smokefree NZ has been estimated to be likely to result in significant future increases in life expectancy for all New Zealanders, but particularly so for Māori (14). While the NZ Government has recently implemented a number of useful measures to reduce tobacco smoking (eg, extension of the yearly programme of tobacco tax increases until 2020, a law requiring standardised tobacco packaging, and removal of point-of-sale tobacco displays), more substantive action is needed to achieve the Smokefree 2025 goal, particularly so for Māori (13). Interventions that may particularly benefit Māori, and hence reduce tobacco-related inequalities, may include tobacco tax increases beyond 2020 (as per NZ modelling work (15) indicating that tobacco tax delivers higher per capita health gains for Māori and is a highly cost-saving intervention). Also there could be more mass media campaigns to support quitting that are specifically designed for a Māori audience eg, the successful “Its About Whanau” campaign (16,17). More profound interventions to ensure rapid progress of the tobacco endgame towards the NZ Government’s 2025 goal might include:
- A sinking lid on commercial sales of tobacco (18) – given such a strategy may particularly affect Māori smokers (given their currently higher smoking rates/demand for tobacco).
- Major levels of tobacco retail outlet reduction (19,20). Research suggests tobacco retail outlets are disproportionally located in most deprived neighbourhoods of NZ (where Māori are over-represented (21)), and easy access has been associated with increased smoking uptake and reduced cessation.
- A smokefree generation (ie, no one born after a particular year is allowed to purchase tobacco (22)) – with this measure particularly having potential to reduce future smoking rates among Māori, with observed smoking rates nearly twice as high among young Māori compared to non-Māori (to be detailed further in a forthcoming blog).
Fortunately, the NZ public appear to be broadly supportive of such endgame strategies (23). Such strategies are also consistent with international calls to end the global tobacco epidemic (24).
Accelerating declines in CVD
The decades-long decline in CVD rates is a public health success story for NZ – but further reductions could reduce ethnic inequalities in health. Modelling work for NZ has suggested that there are many population-wide dietary salt (sodium) reduction measures that are likely to provide greater per capita health gain for Māori relative to non-Māori (25-27). CVD risk screening in primary care is high, albeit with some ethnic inequality for Māori vs non-Māori (at 86% vs 92% coverage respectively) (28). Appropriately, the target age-range for such screening for Māori already starts at a younger age to assist with achieving equity goals. Also of note is that there have been successful campaigns to increase preventive CVD pharmacotherapy among Māori eg, around taking statins (29).
Improving health services
Another area for health service improvements is in terms of receipt of various cancer treatments between ethnic groups in NZ (30) (a pattern that is also seen internationally (31)). We acknowledge that some of these inequalities are challenging to address given higher levels of co-morbidities among ethnic groups can be perceived as limiting treatment options. But further improvements in diabetes care may also be a likely fertile area for progress here. The enhanced use of cancer care coordinators might also help modestly (with our previous work suggesting that these are a likely cost-effective intervention in the NZ setting (32)). Health services that screen and treat the bacteria that causes stomach cancer may also particularly benefit Māori and Pacific peoples (with this likely to be cost-effective in modelling work we have done (33) [see also this blog]).
Our new study found favourable declines in all-cause mortality rates, over time, for Māori, Pacific peoples and the European/Other ethnic group. Also of note was that ethnic mortality inequalities are generally stable or even falling in absolute terms, though increasing in relative terms. To further address both absolute and relative inequalities, NZ policy-makers have many options. These will tend to benefit the health of all groups in NZ society: particularly in the domains of tobacco control, the obesogenic environment and improving health services.
- Bor J, Cohen GH, Galea S. Population health in an era of rising income inequality: USA, 1980–2015. Lancet. 2017;389(10077):1475-1490.
- Stringhini S, Carmeli C, Jokela M, Avendano M, Muennig P, Guida F et al. Socioeconomic status and the 25 x 25 risk factors as determinants of premature mortality: a multicohort study and meta-analysis of 1.7 million men and women. Lancet. 2017;389(10075):1229-1237.
- Disney G, Teng A, Atkinson J, Wilson N, Blakely T. Changing ethnic inequalities in mortality in New Zealand over 30 years: linked cohort studies with 68.9 million person-years of follow-up. Popul Health Metr. 2017;15:15. https://pophealthmetrics.biomedcentral.com/articles/10.1186/s12963-017-0132-6
- Blakely T, Tobias M, Atkinson J. Inequalities in mortality during and after restructuring of the New Zealand economy: repeated cohort studies. BMJ. 2008;336(7640):371-375.
- Standing G. The precariat: The new dangerous class: A&C Black; 2011.
- More young people with NCEA Level 2 [http://www.education.govt.nz/ministry-of-education/government-education-initiatives/better-public-services/more-young-people-with-ncea-level-2/]
- GBD 2013 Risk Factors Collaborators, Forouzanfar M, Alexander L, Anderson H, Bachman V, Biryukov S et al. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks in 188 countries, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet. 2015;386:2287-2323.
- Ministry of Health: Annual Update of Key Results 2014/15: New Zealand Health Survey. Wellington: Ministry of Health, 2015. http://www.health.govt.nz/publication/annual-update-key-results-2014-15-new-zealand-health-survey
- Teng AM, Atkinson J, Disney G, Wilson N, Sarfati D, McLeod M et al. Ethnic inequalities in cancer incidence and mortality: census-linked cohort studies with 87 million years of person-time follow-up. BMC Cancer. 2016;16(1):755.
- Falbe J, Thompson HR, Becker CM, Rojas N, McCulloch CE, Madsen KA. Impact of the Berkeley Excise Tax on Sugar-Sweetened Beverage Consumption. Am J Public Health. 2016;106(10):1865-1871.
- Silver LD, Ng SW, Ryan-Ibarra S, Taillie LS, Induni M, Miles DR et al. Changes in prices, sales, consumer spending, and beverage consumption one year after a tax on sugar-sweetened beverages in Berkeley, California, US: A before-and-after study. PLoS Med. 2017;14(4):e1002283.
- Colchero MA, Popkin BM, Rivera JA, Ng SW. Beverage purchases from stores in Mexico under the excise tax on sugar sweetened beverages: observational study. BMJ. 2016;352:h6704.
- van der Deen FS, Ikeda T, Cobiac L, Wilson N, Blakely T. Projecting future smoking prevalence to 2025 and beyond in New Zealand using smoking prevalence data from the 2013 Census. N Z Med J. 2014;127(1406):71-79.
- Blakely T, Carter K, Wilson N, Edwards R, Woodward A, Thomson G et al. If nobody smoked tobacco in New Zealand from 2020 onwards, what effect would this have on ethnic inequalities in life expectancy? N Z Med J. 2010;123(1320):26-36.
- Blakely T, Cobiac LJ, Cleghorn CL, Pearson AL, van der Deen FS, Kvizhinadze G et al. Health, health inequality, and cost impacts of annual increases in tobacco tax: Multistate life table modeling in New Zealand. PLoS Med. 2015;12(7):e1001856. [Correction at: http://journals.plos.org/plosmedicine/article?id=1001810.1001371/journal.pmed.1002211].
- Wilson N, Grigg M, Graham L, Cameron G. The effectiveness of television advertising campaigns on generating calls to a national Quitline by Maori. Tob Control. 2005;14(4):284-286.
- Grigg M, Waa A, Bradbrook SK. Response to an indigenous smoking cessation media campaign – it’s about whanau. Aust N Z J Public Health. 2008;32(6):559-564.
- Wilson N, Thomson GW, Edwards R, Blakely T. Potential advantages and disadvantages of an endgame strategy: a ‘sinking lid’ on tobacco supply. Tob Control. 2013;22 Suppl 1:i18-i21.
- Pearson AL, van der Deen FS, Wilson N, Cobiac L, Blakely T. Theoretical impacts of a range of major tobacco retail outlet reduction interventions: modelling results in a country with a smoke-free nation goal. Tob Control. 2014;24:e32-e38.
- Pearson AL, Cleghorn CL, van der Deen FS, Cobiac LJ, Kvizhinadze G, Nghiem N et al. Tobacco retail outlet restrictions: health and cost impacts from multistate life-table modelling in a national population. Tob Control. 2016;(E-publication 22 September).
- Marsh L, Doscher C, Robertson LA. Characteristics of tobacco retailers in New Zealand. Health Place. 2013;23:165-170.
- Berrick AJ. The tobacco-free generation proposal. Tob Control. 2013;22 Suppl 1:i22-26.
- Edwards R, Wilson N, Peace J, Weerasekera D, Thomson GW, Gifford H. Support for a tobacco endgame and increased regulation of the tobacco industry among New Zealand smokers: results from a National Survey. Tob Control. 2012;[E-publication 27 April].
- Beaglehole R, Bonita R, Yach D, Mackay J, Reddy KS. A tobacco-free world: a call to action to phase out the sale of tobacco products by 2040. Lancet. 2015;385(9972):1011-1018.
- Nghiem N, Blakely T, Cobiac LJ, Pearson AL, Wilson N. Health and economic impacts of eight different dietary salt reduction interventions. PLoS One. 2015;10(4):e0123915.
- Wilson N, Nghiem N, Eyles H, Mhurchu CN, Shields E, Cobiac LJ et al. Modeling health gains and cost savings for ten dietary salt reduction targets. Nutr J. 2016;15:44.
- Nghiem N, Blakely T, Cobiac LJ, Cleghorn CL, Wilson N. The health gains and cost savings of dietary salt reduction interventions, with equity and age distributional aspects. BMC Public Health. 2016;16(1):423.
- Ministry of Health. How is my DHB performing? 2015/16 (Quarter 2 October–December). 2016. http://www.health.govt.nz/new-zealand-health-system/health-targets/how-my-dhb-performing/how-my-dhb-performing-2015-16. 2016.
- Norris P, Horsburgh S, Becket G, Keown S, Arroll B, Lovelock K et al. Equity in statin use in New Zealand. J Primary Health Care. 2014;6(1):17-22.
- Hill S, Sarfati D, Robson B, Blakely T. Indigenous inequalities in cancer: what role for health care? Aust N Z J Surg. 2013;83(1-2):36-41.
- Smedley B, Stith A, Nelson A (eds.): Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care. Washington: National Academy Press; 2002.
- Blakely T, Collinson L, Kvizhinadze G, Nair N, Foster R, Dennett E et al. Cancer care coordinators in stage III colon cancer: a cost-utility analysis. BMC Health Serv Res. 2015;15:306.
- Teng AM, Kvizhinadze G, Nair N, McLeod M, Wilson N, Blakely T. A screening program to test and treat for Helicobacter pylori infection: Cost-utility analysis by age, sex and ethnicity. BMC Infect Dis. 2017;17(1):156.