Social inequality and ethnic differences in smoking in New Zealand

Abstract

This study tests a generalisation of the ‘Wilkinson’ thesis that the greater a nation's income inequality, the poorer the average national health status. We consider the effect of socio-economic inequality upon ethnic variations in smoking in New Zealand. Analysis of Maori and Pakeha (New Zealanders of European descent) smoking rates from the 1996 Census is conducted for 73 Territorial Local Authority areas in New Zealand, disaggregated by gender and rural–urban location. Partial correlation is used to control for absolute levels of deprivation and examine the independent effect of ethnic social inequality upon smoking rates. The level of social inequality between Maori and Pakeha has an independent effect on Maori smoking rates. Pakeha smoking rates by contrast are more sensitive to variations in absolute rather than relative deprivation. The effect of inequality is greatest for Maori women, especially among urban residents. By contrast, among Maori men the effects are greatest in rural areas. The results provide some qualified support for the Wilkinson thesis and suggest that policies which address fundamental issues of social inequality will play a small, but significant, role in helping to reduce high smoking rates amongst Maori.

Introduction

In most developed countries it has long been recognised that there are historically persistent inequalities in health and that the ‘health gaps’ between advantaged and disadvantaged population groups have widened or changed little in recent years, despite rising national wealth (Coburn, 2000). New Zealand is no exception to this trend with research on mortality (Davis, Graham, & Pearce, 1999) and hospital admissions (Barnett & Lauer, 2003) indicating persistent inequalities between social and ethnic groups. Such trends are also characteristic of smoking in New Zealand. Social and ethnic group differences have remained significant over time and show little sign of decreasing (Durie, 1998; Ministry Ministry of Maori Development (1998), Ministry of Maori Development (1999)). While many countries have recorded decreased levels of smoking (Benzeval, Judge, & Whitehead, 1996), this has been less true of New Zealand where smoking rates, after declining by 10% (1976–91) began to decline less rapidly in the 1990s (Ministry of Health, 2002). Declines in smoking have been more typical of Pakeha (New Zealanders of European descent) than Maori. While smoking prevalence among Europeans decreased by approximately 3% between 1990 and 2001, no such trend was evident among the Maori or Pacific Island populations (Ministry of Health, 2002). Smoking rates, especially among Maori women, continue to be among the highest in the world (Broughton & Lawrence, 1993). Smoking thus remains a major contributor to ethnic disparities in life chances (Ministry of Health, 2001a).

Internationally, much work has focused on the relationship of health to socio-economic status (Mackenbach, Kunst, Groenhof, Borgan, & Costa, 1999) and, to a lesser extent, to ethnicity (Lillie-Blanton & Laveist, 1996), and health. Only recently has research begun to focus on inequality, that is socio-economic differentials, as a major determinant of varying levels of health status. In what has become a provocative thesis, Wilkinson (1996) has contended that the greater a nation's income inequality, the poorer the average national health status. Despite evidence at a variety of spatial scales, this thesis has been challenged (Judge, 1995; Judge, Mulligan, & Benzeval, 1998; Fiscella & Franks, 2000; Mackenbach, 2002). Criticisms that the thesis is “wanting in many respects” (Mellor & Milyo, 2001) or “is far from compelling” (Wagstaff & Van Doorslaer, 2000) have a certain validity. Nonetheless, two decades of neoliberalism have left a legacy of widening income and health inequalities in many countries (Pappas, Queen, Hadden, & Fisher, 1993; McCarron, Davey Smith, & Womersley, 1994; VanDoorslaer, Wagstaff, Bleichrodt, & Calonge, 1997; Shaw, Gordon, Dorling, Mitchell, & Davey Smith, 2000) that would seem to be consistent with Wilkinson's views.

This paper extends work on the applicability of the Wilkinson hypothesis to a new focus. It considers the relationship between socio-economic inequality and ethnic variations in smoking behaviour in Aotearoa/New Zealand. The choice of smoking behaviour, rather than the more usual measures of mortality or self-assessed health, provides arguably a more direct test of the Wilkinson thesis as it is causally prior to both. More generally the focus on smoking and inequality is timely in view of increased social inequality in New Zealand (Mowbray, 2001) and calls by writers, such as Coburn (2000), for greater attention to the contextual factors which underlie the presence of health inequalities. While poverty and smoking have received considerable attention in New Zealand (e.g., Crampton et al., 2000), little attention has been devoted to the relationship between smoking and social inequality. If such a link exists we would expect income inequality to be more strongly associated with smoking by Maori rather than Pakeha. Maori, as a generally more deprived group, are likely to be more vulnerable to the psychosocial and material consequences of living in an unequal society (Diez-Roux et al., 2000).

With such issues in mind, the specific objective of this paper is to examine the extent to which measures of social inequality help to explain ethnic variations in smoking. We also consider whether our findings for smoking prevalence are replicated for smoking cessation. We test three hypotheses:

• that relative social inequality has an impact upon smoking rates, and rates of smoking cessation, independent of differences in absolute deprivation;

• that this impact will be most evident amongst the Maori population, the indigenous population of New Zealand, given higher rates of disadvantage amongst Maori compared to the dominant Pakeha population;

• that the relationship between inequality, smoking and smoking cessation will reflect gender differences and be most pronounced among Maori women compared to Maori men.

The paper is organised into six sections. In the first, we provide an overview of the social inequality hypothesis. We then examine its relevance to smoking. The next section discusses the structural implications of the changing socio-economic position of the indigenous Maori population in New Zealand. After an outline of the methodology of the study, we present our results in the fifth, empirical, section of the paper. In the final section, we examine some of the theoretical and policy implications of our findings.