Mª Isabel Ortega Díaz

Dr. Mª Isabel Ortega Díaz


Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 December 2012 in Water Resources Management
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Francisco González-GómezFrancisco González-Gómez
Francisco González-Gómez
MGMiguel A. García‐Rubio
Miguel A. García‐Rubio
FAFrancisco Alcalá-Olid
Francisco Alcalá-Olid
MDMª Isabel Ortega Díaz
Mª Isabel Ortega Díaz

1 March 2017 in Gaceta Sanitaria
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Journal Article
Open access
CPCarmen Pérez-Romero
Carmen Pérez-Romero
MDMª Isabel Ortega Díaz
Mª Isabel Ortega Díaz
RORicardo Ocaña-Riola
Ricardo Ocaña-Riola
JMJosé Jesús Martín-Martín
José Jesús Martín-Martín
To analyse the technical efficiency and productivity of general hospitals in the Spanish National Health Service (NHS) (2010-2012) and identify explanatory hospital and regional variables. 230 NHS hospitals were analysed by data envelopment analysis for overall, technical and scale efficiency, and Malmquist index. The robustness of the analysis is contrasted with alternative input-output models. A fixed effects multilevel cross-sectional linear model was used to analyse the explanatory efficiency variables. The average rate of overall technical efficiency (OTE) was 0.736 in 2012; there was considerable variability by region. Malmquist index (2010-2012) is 1.013. A 23% variability in OTE is attributable to the region in question. Statistically significant exogenous variables (residents per 100 physicians, aging index, average annual income per household, essential public service expenditure and public health expenditure per capita) explain 42% of the OTE variability between hospitals and 64% between regions. The number of residents showed a statistically significant relationship. As regards regions, there is a statistically significant direct linear association between OTE and annual income per capita and essential public service expenditure, and an indirect association with the aging index and annual public health expenditure per capita. The significant room for improvement in the efficiency of hospitals is conditioned by region-specific characteristics, specifically aging, wealth and the public expenditure policies of each one.

28 July 2022 in Health Policy
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Journal Article
Open access
MDMª Isabel Ortega Díaz
Mª Isabel Ortega Díaz
Juan Carlos MartinJuan Carlos Martin
Juan Carlos Martin
In Spain the health care cuts have been the norm after the international economic crisis. The aim of this study is fourfold: (1) to measure hospital performance analysing two different perspectives: technical efficiency and quality; (2) to determine how technically efficient hospitals operate when faced with undesirable production; (3) to determine whether a potential trade-off between efficiency and quality exists or not; and (4) to propose a methodology to detect which hospitals could reduce their running costs without jeopardizing the quality of the services provided. Budget cutbacks imposed in Spain should focus solely on these hospitals, unless an increase in undesirable production is considered acceptable. In this paper a SBM (slacks-based measure) of efficiency model is employed incorporating undesirable outputs using the case-mix adjusted deaths of patients. The study is carried out using information from 232 general hospitals in Spain. We find four different groups of hospitals based on the relationship between efficiency and undesirable outputs. We show that undesirable outputs affect the measurement of technical efficiency, proposing a tool that allows the identification of hospitals where efficiency can be increased, that is, where budget cuts and/or more production outputs can be implemented without necessarily increasing the undesirable output.

1 July 2019 in Gaceta Sanitaria
Verified
Journal Article
Open access
CPCarmen Pérez-Romero
Carmen Pérez-Romero
MDMª Isabel Ortega Díaz
Mª Isabel Ortega Díaz
RORicardo Ocaña-Riola
Ricardo Ocaña-Riola
JMJosé Jesús Martín-Martín
José Jesús Martín-Martín
To analyze technical efficiency by type of property and management of general hospitals in the Spanish National Health System (2010-2012) and identify hospital and regional explanatory variables. 230 hospitals were analyzed combining data envelopment analysis and fixed effects multilevel linear models. Data envelopment analysis measured overall, technical and scale efficiency, and the analysis of explanatory factors was performed using multilevel models. The average rate of overall technical efficiency of hospitals without legal personality is lower than hospitals with legal personality (0.691 and 0.876 in 2012). There is a significant variability in efficiency under variable returns (TE) by direct, indirect and mixed forms of management. The 29% of the variability in TE es attributable to the Region. Legal personality increased the TE of the hospitals by 11.14 points. On the other hand, most of the forms of management (different to those of the traditional hospitals) increased TE in varying percentages. At regional level, according to the model considered, insularity and average annual income per household are explanatory variables of TE. Having legal personality favours technical efficiency. The regulatory and management framework of hospitals, more than public or private ownership, seem to explain technical efficiency. Regional characteristics explain the variability in TE.

MDMª Isabel Ortega Díaz
Mª Isabel Ortega Díaz
RORicardo Ocaña-Riola
Ricardo Ocaña-Riola
CRCARMEN PÉREZ ROMERO
CARMEN PÉREZ ROMERO
JMJosé Jesús Martín-Martín
José Jesús Martín-Martín
Objective: To evaluate the relationship between the ownership structure of hospitals and the possibility of their being positioned on the frontier of technical efficiency in the economic crisis period 2010–2012, adjusting for hospital variables and regional characteristics in the areas where the Spanish National Health System (SNHS) hospitals are located. Methods: 230 National Health System hospitals were studied over the two-year period 2010–2012 according to their ownership structure—public hospitals, private hospitals and public–private partnership (PPP)—data envelopment analysis orientated to inputs was used to measure the overall technical efficiency, pure efficiency and efficiency of scale. A generalised linear mixed model (GLMM) with binomial distribution and logit link function was used to analyse the hospital and regional variables associated with positioning on the frontier. Results: There are substantial differences between the average pure technical efficiency of public, private and PPP hospitals, as well as a greater number of PPP models being positioned on the efficiency frontier (91.67% in 2012). The odds of being positioned on the frontier are 41.7 times higher in PPP models than in public hospitals. The average annual household income per region is related to the greater odds of hospitals being positioned on the frontier of efficiency. Conclusions: During the most acute period of recession in the Spanish economy, PPP formulas favoured hospital efficiency, by increasing the odds of being positioned on the frontier of efficiency when compared to private and public hospitals. The position on the frontier of efficiency of a hospital is related to the wealth of its region.

RORicardo Ocaña-Riola
Ricardo Ocaña-Riola
CRCARMEN PÉREZ ROMERO
CARMEN PÉREZ ROMERO
MDMª Isabel Ortega Díaz
Mª Isabel Ortega Díaz
JMJosé Jesús Martín-Martín
José Jesús Martín-Martín
Background: This article proposes a methodological innovation in health economics for the second stage analysis of technical efficiency in hospitals. It investigates the relationship between the installed capacity in regions and hospitals and their ownership structure. Methods: A multilevel zero-one inflated beta regression model is employed to model pure technical efficiency more adequately than other models frequently used in econometrics. Results: Compared to publicly managed hospitals, the mean efficiency index of hospitals with public-private partnership (PPP) formulas was 4.27-fold. This figure was 1.90-fold for private hospitals. Concerning the efficiency frontier, the odds ratio (OR) of PPP models vs. public hospitals was 42.06. The OR of private hospitals vs. public hospitals was 8.17. A one standard deviation increase in the percentage of beds in intensive care units increases the odds of being situated on the efficiency frontier by 50%. Conclusions: The proportion of hospital beds in intensive care units relates to a higher chance of being on the efficiency frontier. Hospital ownership structure is related to the mean efficiency index of Spanish National Health Service hospitals, as well as the odds of being situated on the efficiency frontier.