Factors underlying the growth of hospital expenditure in Spain in a period of unexpected economic shocks: a dynamic analysis on administrative data

Abstract

Aims: We sought to understand the evolution of Spanish public hospital expenditure by assessing itselasticity to volume versus price, controlling for need and case severity, from January 2003 to December2015, a period of unexpected economic shocks. Method: Observational study of administrative data characterising hospitals in the Spanish NationalHealth System. Public hospital expenditure was modelled using SARIMAX in a two-step approach aimingat: a) eliciting structural changes in the monthly time-series; and, b) analysing the reaction of expenditureto the behaviour of its direct underlying factors over the sub-periods identified in the first step. Results: From January 2003 to December 2015, two structural changes were elicited, splitting this time-span into three sub-periods. The quantities of hospital services offered (mainly inpatient medical andsurgical activity) were consistently shown as the main drivers of expenditure. Overall, hospital expen-diture was inelastic to all the factors analysed, specially to quasi-prices; similar results were obtainedacross sub-periods of analysis. Conclusion: Factors associated to quantities (as compared to quasi-prices) were the main drivers ofhospital expenditure in the period analysed, particularly after the economic shock. However, hospitalexpenditure was inelastic to both factors giving prominence to the economic cycle fluctuations as astrong inducer of the hospital expenditure trends in Spain.