INTRODUCTION Changes in the conceptualization of health and illness have led to development of theory and methods to study health-related quality of life. One instrument used frequently to measure this concept is the SF-12 survey, included in the Second National Health Survey carried out in Chile between 2009 and 2010.

OBJECTIVE Estimate the association between socioeconomic status stratifiers and health-related quality of life in the adult population residing in Chile.

METHODS We conducted a cross-sectional study of a subsample of the National Health Survey, in the population aged ≥25 years. Health-related quality of life was operationalized from two SF-12 composite scales: physical health-related quality of life and mental health-related quality of life. Both were categorized as good or poor relative to their median scores. Socioeconomic status stratifiers were education, employment status and monthly per capita household income. Multiple logistic regression models were generated for physical health-related quality of life and mental health-related quality of life, according to socioeconomic status stratifiers adjusted for several covariates.

RESULTS The sample comprised 4473 respondents, 51.6% women, median age 47.8 years. The probability of poor quality of life was higher in persons with only primary school education, those not in the workforce and those whose monthly income was below 100,815 Chilean pesos (US$140); the effect was stronger for physical health-related quality of life (OR 2.8, 95% CI 1.8–4.2; OR 1.7, 95% CI 1.2–2.3 and OR 2.2, 95% CI 1.3–3.8, respectively) than for mental health-related quality of life (OR 1.4, 95% CI 1.1–1.8; OR 1.6, 95% CI 1.2–2.2 and OR 1.9, 95% CI 1.1–3.0, respectively).

CONCLUSIONS The probability of poor health-related quality of life is higher in the worst socioeconomic status strata, and the effect is most pronounced in the most vulnerable groups. The direct effect of social stratifiers on living conditions and access to services—both strong
influences on subjective health—would explain this finding and highlight the need to adopt equity-oriented strategies aimed at addressing the impact of socioeconomic status on health-related quality of life.

KEYWORDS Health-related quality of life, socioeconomic factors, social class, health status disparities, inequalities, health equity, health disparities, social determinants of health, Chile