Is inequity undermining Australia's 'universal' health care system? Socio-economic inequalities in the use of specialist medical and non-medical ambulatory health care

Objectives: To quantify need-adjusted socioeconomic inequalities in medical and non-medical ambulatory health care in Australia and to examine the effects of specific interventions, namely concession cards and private health insurance (PHI), on equity. Methods: We used data from a 2004 survey of 10,905 Australian women aged 53 to 58 years. We modelled the association between socio-economic status and health service use - GPs, specialists, hospital doctors, allied and alternative health practitioners, and dentists - adjusting for health status and other confounding variables. We quantified inequalities using the relative index of inequality (RII) using Poisson regression. The contribution of concession cards and PHI in promoting equity/inequity was examined using mediating models. Results: There was equality in the use of GP services, but socio-economically advantaged women were more likely than disadvantaged women to use specialist (RII=1.41, 95% CI:1.26-1.58), allied health (RII=1.21,1.12-1.30) , alternative health (RII=1.29,1.13-1.47) and dental services (RII=1.61,1.48-1.75) after adjusting for need, and they were less likely to visit hospital doctors (RII=0.74,0.57-0.96). Concession cards reduced socio-economic inequality in GP but not specialist care. Inequality in dental and allied health services was partly explained by inequalities in PHI. Conclusions and implications: Substantial socio-economic inequity exists in use of specialist and non-medical ambulatory care in Australia. This is likely to exacerbate existing health inequalities, but is potentially amenable to change.