A utilização dos gráficos de controle: uma aplicação na área da saúde

Abstract

Statistical methods and control charts are important resources to detect changes in various kinds of processes. It has been noticed along the years that these charts have been theoretically refined and, before the analogy and the simplicity of some statistical methods of quality control, it has been happening a great widespread and encouragement to apply the charts in the data analysis of different health fields. With the purpose of making a collaborative work with teaching and health service professionals, this dissertation aims to describe and exemplify some main kinds of statistical charts of quality control to be applied in the quality monitoring in hospitals. To accomplish this task, it was obtained from the hospital at the Federal University of Santa Maria Brazil, during the period of 2000 to 2005, some indexes: general hospital occupation tax, emergency room occupation tax, Psychiatric unit occupation tax, newborn Intensive Care Unit occupation tax and institutional mortality tax dialysis. First of all, a descriptive analysis was conducted to verify presuppositions about normality and independence, required by the traditional techniques of controlling chart. Lately, models ARIMA of Box & Jenkins methodology were adjusted to the series that presented autocorrelation, to elaborate a subsequently controlling chart based on the residues. Many points out of the controlling limits to the series analyzed were observed, besides the presence of a great variability to the general hospital occupation tax and the institutional morality of dialysis. The emergency room occupation tax, the psychiatric unit and newborn Intensive Care Unit occupation tax were the ones that presented more stability. Comparing the charts used, it was identified the advantages of CUSUM charts in detecting precociously changes occurred in the process, besides identifying modifications in small magnitudes than X-bar chart. Despite the initial difficulties in implementing some more complex methodologies, the application of these charts is a pretty efficient resource to control the processes, due to the great number of variables which could be monitored in a hospital environment or any other sector related to people health, bringing improvements to other aspects such as personal, familiar and professional ones.