Adjusted Clinical Groups (ACGs) explain the utilization of primary care in Spain based on information registered in the medical records: A cross-sectional study
Introduction
Methods of measuring the burden of illness in populations and the resulting need for health services are becoming increasingly relevant to health administrators, managers, and policymakers as escalating health care costs have led to seek strategies to improve health care system equity, effectiveness, and efficiency. Populations health care needs have been assessed from indirect measures developed from demographics, mortality rates, population surveys, and diagnosis-based case-mix systems [1]. Case-mix tools have been developed to quantify overall requirements for resources based on diagnoses for individuals and, when aggregated, for populations [2], [3], [4]. Diagnosis-based systems use existing administrative databases in which diagnostic codes and patients’ demographic data are collected.
The Adjusted Clinical Groups (ACGs; formerly the Ambulatory Care Groups) is one of such instrument that classifies each patient into one mutually exclusive category considering his/her age and sex and all the diagnoses established over a period of time, usually 12 months [5], [6]. The ACG approach is being applied to adjust capitation payment rates and for physician profiling in the United States [7], [8], [9], [10] and Canada [11], [12], and as a morbidity adjustment method in health care services research [13], [14], [15], [16], [17], [18]. On the other hand, studies testing the ability of ACGs to describe the burden of illness in other countries have been reported [19], [20], [21].
In Spain, a few research studies have evaluated the performance of ACGs in primary care. It has been shown that the ACGs case-mix system can explain more than 50% of the variance in health services utilization by primary care patients [22], [23], [24]. From a practical point of view, the usefulness of diagnosis-based case-mix systems in our environment is threatened by the absence of health databases for management purposes. Moreover, physicians are not accustomed to register information in a standardized manner and there are many differences among professionals in the quality and completeness of physician recording. The aim of this study was to establish the validity of a diagnosis-based case mix system in real conditions of the daily practice. For this purpose, a first objective of the study was to assess whether the annotations that physicians routinely make in their patients’ medical records allow the use of the ACGs classification system. A second objective of the study was to determine the ability of the ACGs system to explain the utilization of other resources, such as referrals to other health care levels, requests for radiographic studies and laboratory tests, and number and cost of prescriptions.
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Setting
Forty-six general practitioners and 10 pediatricians from primary health care centers of the Osakidetza/Basque Health Service in Spain participated in a cross-sectional study. Of the total 56 medical offices, 29 were located in urban areas (metropolitan area of Bilbao), 13 in rural municipalities (population < 3000 inhabitants), and 14 in intermediate towns (population between 3000 and 16,000 inhabitants). The Osakidetza/Basque Health Service is a public organization in which universal tax-funded
Results
The mean age of the study population was 42.9 years (95% confidence interval 42.8–43.1 years). Of the total 84,136 persons, 7155 (8.5%) were under 15 years of age and 16,081 (19.1%) were older than 65 years. The percentage of female patients was 50.4%.
The mean number of diagnoses and ACG case-mix system groups per patient and the distribution of the study population according to ADGs in scenarios 1 and 3 are shown in Table 3, Table 4. The results of several multiple linear regression models
Principal findings
In our primary care setting, diagnosis-based databases are not available, which is in contrast to the in-patient care setting where the minimal data set for hospitals has been implemented for more than one decade, allowing hospital discharges to be classified using a case-mix system [31]. In this study, the collection of data directly from the computerized medical records has made also possible to assess the reliability and feasibility of this information source to obtain data at a population
Conclusions
The present results confirm that the ACGs case-mix system offers a measure that summarizes the “morbidity load” of a population, allowing to explain an important part of the use of health care resources in primary care. In the absence of health databases for administrative purposes, the use of the ACGs system is feasible from information that physicians registered in the computerized medical records of their patients with the main purpose of serving as a support for the individual care.
Acknowledgments
We thank Marta Pulido, MD, for editing the manuscript and editorial assistance. A grant (00/0638) from Fondo de Investigación Sanitaria was received in support of this project.
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2015, European Journal of Operational ResearchCitation Excerpt :Moreover, instead of only considering activity-related indicators, it uses a more solid performance indicator represented by hospitalization rates for ACSCs. In addition, the study population is adjusted for health status through a morbidity index (based on ACGs), which is a sophisticated measure validated in our context (Orueta, Urraca, Berraondo, Darpon, & Aurrekoetxea, 2006). The population is also adjusted for age and for the socio-economic level of the area of residence.
Quantifying morbidity burdens and medical utilization of children with intellectual disabilities in Taiwan: A nationwide study using the ACG case-mix adjustment system
2012, Research in Developmental DisabilitiesCitation Excerpt :The system uses all medical diagnosis codes from claims data to quantify morbidities for individuals and, when aggregated, for populations. The validity and reliability of the ACG System has been verified and widely applied in the United States (Rosen et al., 2001; Starfield et al., 1991; Weiner et al., 1991), Canada (Reid et al., 2001; Reid, Roos, MacWilliam, Frohlich, & Black, 2002), Sweden (Carlsson, Borjesson, & Edgren, 2002; Carlsson, Strender, Fridh, & Nilsson, 2004; Engstrom, Carlsson, Ostgren, Nilsson, & Borgquist, 2006), and Spain (Orueta et al., 1999; Orueta, Urraca, Berraondo, Darpon, & Aurrekoetxea, 2006). The validity and reliability of the ACG System using the National Health Insurance (NHI) claims data has also been documented (Chang, Lee, & Weiner, 2010; Chang & Weiner, 2010; Lee, 2008; Lee & Huang, 2008).
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