The link between out-of-pocket costs and inequality in specialist care in Australia.

Objective Out-of-pocket (OOP) costs could act as a potential barrier to accessing specialist services, particularly among low-income patients. The aim of this study is to examine the link between OOP costs and socioeconomic inequality in specialist services in Australia. Methods This study is based on population-level data from the Medicare Benefits Schedule of Australia in 2014-15. Three outcomes of specialist care were used: all visits, visits without OOP costs (bulk-billed services), and visits with OOP costs. Logistic and zero-inflated negative binomial regression models were used to examine the association between outcome variables and area-level socioeconomic status after controlling for age, sex, state of residence, and geographic remoteness. The concentration index was used to quantify the extent of inequality. Results Our results indicate that the distribution of specialist visits favoured the people living in wealthier areas of Australia. There was a pro-rich inequality in specialist visits associated with OOP costs. However, the distribution of the visits incurring zero OOP cost was slightly favourable to the people living in lower socioeconomic areas. The pro-poor distribution of visits with zero OOP cost was insufficient to offset the pro-rich distribution among the visits with OOP costs. Conclusions OOP costs for specialist care might partly undermine the equity principle of Medicare in Australia. This presents a challenge to the government on how best to influence the rate and distribution of specialists' services.