The impact of non-monetary factors on the primary care utilization in Portugal. Finite mixture models applied to on-site and truncated samples

Abstract

In the Portuguese National Health Service (NHS) patients have to pay a co-payment of 2€ to visit a GP in the health centres. Therefore, the monetary price associated to each visit is low and, with a high probability, is not a factor that affects the utilization of consultations in health centres. On the other hand, in any health system in which the monetary cost to consume medical care is very low other kind of costs can emerge as determinants of medical care utilization. The Portuguese NHS suffers from several time-related inefficiencies and so, the non-monetary form of co-payment is a non negligible reality. With data in our database we have concluded that the average waiting time to visit a GP is approximately 9 days. Moreover, the average waiting time in the waiting room for a consultation is approximately 1 hour. Therefore, this study aims at analysing the impact of non-monetary factors on the utilization of public GPs. This study can be useful for policy making, as well as for econometric reasons. In the other hand, sometimes the empirical researcher faces non-random samples. So, modelling based on the assumption that we have a simple random sample can be inappropriate and misleading. In this research we face this same situation. Our data resulted from the application of two endogenous sampling schemes: a sample collected on-site and a truncated sample. Therefore each sampling scheme generates a selected sample. Thus, to make valid inference, adequate econometric modelling has to be used. To model our dependent variable, number of visits, and to take into account the unobserved heterogeneity, we relied on a semi-parametric specification through the use of finite mixture models. The data were obtained from the Europep questionnaire, a standardized questionnaire designed to measure primary patient satisfaction in European countries.