Epidemiological and georeferencial analysis of five-year patterns of use of medical services in captive patient population

Abstract

The identification of health problems in the community and the implementation of intervention strategies usually collides with the difficulty of presenting clear, reliable data and mainly useful and intuitive to political decision makers, and it is in this sense that the geographical information systems (GIS) can be of great utility. The technology of the georeference is already accepted as anessential tool for the effective use of the information. Also keeping in mind that in any organization that provides health services the information about use (and costs) of them as well as the characteristics of the user population should be articulated with the organizational development of information systems, using the so called epidemiological reasoning onto the administration of health services, it seemed to us of the most importance to make a critical analysis of the use of services and its patternsalong a five year period on a reference population. So we carried out an analytic observacional study, with a retrospective design, on a five-year period and over a captive population of 5700 people belonging to a health care provider of good socioeconomic level of the City of Buenos Aires, to define the consumption patterns and service usage among them, and to quantify and qualify their demand and variation along time, being also carried out a georeferencial analysis. The usagerates were stratified for diverse usual services as medical consultations, radiology, laboratory analysis, ecography tests and high diagnostic and therapeutic complexity tests, and hospitalizations, accordingto the reference habitat of the people (City of Bs. As., boundaries of the city (the so called Great BA), province of Bs. As. and three main cities: La Plata, Mar del Plata and Bahía Blanca), age group (younger or older than 60 years like first grouping criterion and age categories (10 years) as second grouping criterion, and sex. Accessorily we sub grouped in the Great BA according to one of 3 regions (South, North and Center West) and in the City of Bs. As. according to neighborhood or censal fraction. For each one of the variables we proceeded to the georeferencial plotting using the soft SPSS for stratified and multivariate analysis and the MAP INFO for SIG analysis. We present and comment here the most notorious results of our work, but it admits several other interpretations trata, which are not approached entirely in this occasion and will be object of other communications. Among the outstanding results of our work we mention the significant relationship among age group and sex, and use of services, being evident that those impact positively in the use (p <0.05) being always greater among females than among males (p<0.001) (except in the first year of lifewhen the relationship is inverse) and increasing progressively as the age decade increases, for anyone of the considered services. This fact is not really a new one and it has already been commented by several authors that observed that good part of health expenses is used in giving careto a small number of people, being the variables that more gravitates the age, the illness type, typically the chronic ones and the death. In this sense, our population presents a clear aging process. Linkage constants were generated among key services and the rest. For instance, medical consultations is used thoroughly between 75% and 85% according to the belonging area but if weorder the consumptions for age group and area in a continuum from maximum to minimum we see that the service is used as little as 53% in the males in general or in the males of the province between 21 and 30 years, or as much as 91% in the males or women of the city or the women of Great BA starting from 70 years. The rate average of medical consultations of the population is of 5.4 for user / year but it varies thoroughly among 1.83 for the males of the interior between the 21 and 30 years (p <0.01) and 13.64 (p <0.001) for the women of the city between the 81 and 90 years. The other key service, the hospitalization, was also clearly associated to age, sex and geographical region. This association was clear for the usage ratio, like for the ALOS, and also the expenditure for hospitalization event, per day and for patient/year, in general and for the discrimination made in clinical and surgical hospitalizations. The rates increased according to the decade in both sexs, being greater for the women up to the 5th. or 6th. decade, when the relationshipis inverted. Again, the combination of factors like sex, age decade and residence area conformed a more sensitive polynomial function to detect “risk” of hospitalization that any variable considered alone. Both the rates, ALOS and expenditures for event and for case were minimum among males of the first two decades with residence inside the province of Bs.As. (except in great cities) and were maximum among old women in the city of BA. Indeed, the cost for patient/year varied 2.28 times between masculine interior and feminine city of BA (p <0.01) and the expenditure for hospitalization 1.85 times among these same groups (p <0.05). A certain tendency was also evidenced to the increase in the use rate (although without reaching significance levels) inside a defined influence area of a preferential care giver in the City of Bs. Ace., which would indicate that patients living in the boundaries of this center would use it more than others, being this consistent with what the literature remarks in this sense and lighting fundamental questions on equity, accessibility and geographical distribution of facilities among health care providers that cover wide areas. In this sense it was very clear the almost absolute use of an obstetric center of great fame of this city that captates almost all births in the city of Bs. As. and great part of those from the Great BA, indicating the preference of women and illustrating the central rol that women exercises, as muchas “triagge” in the search of attention like wedge of insertion of the family in the health system. The distribution and characteristic of the beneficiaries and their grade of use of services can represent in operative and practical senses pieces of information of great value when planning the logistics of local resources, like the implementation of family doctors’ programs with population in charge, or the selection of a net system with preferential providers. We think that this is a field and investigation area in frank promising expansion.