The effect of private insurance access on the choice of GP/specialist and public/private provider in Spain.

This paper sheds light into the investigation of differential patterns of utilisation of physician services by populations subgroups that is emerging in a number of studies. Using Spanish data from the National Health Survey of 1997 we try to explain the distinct role of the type of insurance on the choice between specialists and GPs and its intertwining with the choice between private and public providers. We estimate a two-stages probit to conclude that differences in insurance access is the main determinant of both, the choice of sector and the kind of physician contacted, giving rise to very different patterns of consumption of GP and specialist visits. People with only public insurance go 2.8 times to the GP per one time that they visit a specialist; individuals with duplicate coverage have a ratio of GP/specialist visits equal to 1.4 (the combination being public GP and private specialist) and people with only private insurance access actually have an 'inverted' pattern of visits: they contact specialists more often than GPs. Age, sex and health and public supply characteristics also have a distinct and interesting impact on these choices. Finally, equity concerns based on the implied assumption that specialists care is superior to general practitioner care are discussed. Copyright 2003 John Wiley & Sons, Ltd.