Social patterning of chronic disease risk factors: Cross-national and within-country comparisons

Chronic diseases are traditionally thought to be more important in high-income countries, although most of the burden occurs in low- and middle-income countries. Despite a recent global focus on the social determinants of health, few studies have examined socioeconomic gradients in chronic disease risk within poor countries or across countries at different levels of development. This dissertation uses data from the 2002-2003 WHO World Health Surveys (WHS) and the 2005 National Survey of Risk Factors for Non-communicable Diseases in Argentina to examine (1) differences associated with urbanicity in the prevalence and social patterning of chronic disease risk factors across countries (using WHS), (2) differences associated with urbanicity in the prevalence and social patterning of chronic disease risk factors across regions within a middle-income country (Argentina survey), and (3) differences over time (i.e. by age cohort) in the social patterning of smoking behavior within a country in transition (Argentina survey). The WHS study showed that body mass index (BMI), obesity and diabetes were higher at higher levels of urbanicity for both genders. For men, there was little association between urbanicity and prevalence of smoking; for women, higher prevalence of smoking was associated with higher urbanicity. In the least urban countries those of higher socioeconomic position (SEP) had higher BMI, while the opposite pattern was seen in the most urban countries, especially among women. In contrast, smoking was consistently concentrated among those of lower SEP, especially among men, regardless of level of urbanicity. The studies from Argentina found that the socioeconomic patterning of risk factors was modified by provincial-level urbanicity, such that the inverse patterning became stronger or only emerged in more urban settings, particularly for BMI, high blood pressure and diabetes. There was also evidence that the socioeconomic patterning of smoking was changing with successive birth cohorts, and was increasingly concentrated among those of lower SEP, particularly among women. Taken together, these results highlight a trend, globally and within countries, toward increasing burden of chronic disease risk among those of lower socioeconomic position. This is certain to impact future inequities in chronic disease outcomes unless interventions addressing health disparities are undertaken.