Abstract
Background: Health services can reduce inequalities caused by other determinants of health or increase them due to the effect of the inverse care law-the principle that the availability of good quality care tends to vary inversely with the need for it in the population served.
Objective: The purpose of the research was to describe inequalities in the use of nursing services, medical services in primary care, specialist care, and services not fully covered by the Basque public health system in Spain.
Methods: A cross-sectional study of adults aged at least 25 years who completed the 2013 Basque Health Survey (N = 10,454) was conducted. Age-standardized prevalence and prevalence ratios for use of services that are covered and noncovered in the health system were computed. The association of health services usage with socioeconomic variables was estimated using a Poisson regression model with robust variance. The relative index of inequality (RII) was used to measure the magnitude of socioeconomic status inequalities in health service use. All analyses were carried out separately for men and women.
Results: Individuals with lower socioeconomic status were more likely to use primary care (RII = 0.87, 95% CI [0.79, 0.97]) and less likely to use specialist services (RII = 0.82, 95% CI [0.75, 0.89]). Across noncovered health services, inequalities between the highest and lowest social groups were significant in all cases and especially marked in men's use of physiotherapists (RII = 0.46, 95% CI [0.35, 0.61]) and podiatrists (RII = 0.24, 95%CI [0.15, 0.38]).
Discussion: There are significant inequalities in primary and specialist health service use based on individual socioeconomic status, particularly for services that are not provided free of charge within the existing health system. This suggests that health service systems that are not explicitly designed to provide universal access may actually amplify preexisting social and health inequalities within their target populations.