A Spatial Econometric Analysis of the Calls to the Portuguese National Health Line

Paula Simões,Sérgio Gomes,Isabel Natário,M Carvalho,Sandra Aleixo

doi:10.3390/econometrics5020024

Abstract

The Portuguese National Health Line, LS24, is an initiative of the Portuguese Health Ministry which seeks to improve accessibility to health care and to rationalize the use of existing resources by directing users to the most appropriate institutions of the national public health services. This study aims to describe and evaluate the use of LS24. Since for LS24 data, the location attribute is an important source of information to describe its use, this study analyses the number of calls received, at a municipal level, under two different spatial econometric approaches. This analysis is important for future development of decision support indicators in a hospital context, based on the economic impact of the use of this health line. Considering the discrete nature of data, the number of calls to LS24 in each municipality is better modelled by a Poisson model, with some possible covariates: demographic, socio-economic information, characteristics of the Portuguese health system and development indicators. In order to explain model spatial variability, the data autocorrelation can be explained in a Bayesian setting through different hierarchical log-Poisson regression models. A different approach uses an autoregressive methodology, also for count data. A log-Poisson model with a spatial lag autocorrelation component is further considered, better framed under a Bayesian paradigm. With this empirical study we find strong evidence for a spatial structure in the data and obtain similar conclusions with both perspectives of the analysis. This supports the view that the addition of a spatial structure to the model improves estimation, even in the case where some relevant covariates have been included.

Highlights

An initiative to improve accessibility to health care and to rationalize the use of existing resources was carried out by the Portuguese Health Ministry through the creation of a national health line, Econometrics 2017, 5, 24; doi:10.3390/econometrics5020024 www.mdpi.com/journal/econometricsLS24, in April 2007 (Portal of the National Portuguese Health Service 2015)
The data considered in this study were provided by the Support Unit of the Call Center of the National Health Service of the Portuguese Directorate-General of Health. It is a comprehensive data set of the calls recorded by the LS24 health line in the year 2014 and includes information such as user’s gender, residence, age, call’s day of the week, together with the health problem specification
Within the scope of the spatial econometric methods and resorting to Bayesian hierarchical and autoregressive methodology, their application to study of the number of TAE calls to the national health line, LS24, revealed spatial-correlation and the addition of spatial structure in the models improved estimation

Summary

Introduction

LS24, in April 2007 (Portal of the National Portuguese Health Service 2015). These objectives are accomplished by the LS24 service which directs users to the most appropriate institutions of the national public health service or by counseling self-care home measures. To model the number of calls to LS24 in each municipality with spatial models, given the discrete nature of data (counts), an alternative is to use a hierarchical Bayesian model with covariates (Banerjee et al 2004). This approach allows data to have any distribution where, in this case, the Poisson is the obvious choice. The spatial structure assumed for the risk of what is being counted is included, in the first level of the hierarchy, through a prior distribution of spatially structured random effects

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Conclusion