Regenstrief Conference. Marshall, IN, USA, 1996/09/04.
Researchers are increasingly interested in examining costs of care, and large administrative and clinical databases have made relevant data readily available.
Because a few patients incur high costs relative to most patients, the distribution of cost data is often skewed.
How robust are the usual methods of cost analysis against the skewed distribution of cost data ?
To determine the methods commonly used for comparing cost data, describe their limitations, and provide an alternate method of analysis.
Review of statistical methods used in studies of medical costs published in medical journals between January 1991 and January 1996.
Description of a Z-score method appropriate for testing the equality of mean costs between two log-normal samples ; and reanalysis of published two-sample comparison results done by using the Z-score method.
For two-sample comparisons, three methods were commonly used : the Student t-test on untransformed costs, the Wilcoxon test on untransformed costs, and the Student t-test on log-transformed costs.
The t-test on untransformed costs ignores the skewness in cost data, the Wilcoxon test ignores unequal variances, and the t-test on log-transformed costs tests the wrong null hypothesis unless variances in the log-scale are equal.
Eleven articles included two-sample tests and had enough information to allow reanalysis of the data using the Z-score method. (...)
Mots-clés Pascal : Système gestion base donnée, Etude comparative, Méthodologie, Coût, Identification spécifique, Maladie, Analyse statistique, Homme, Organisation santé, Economie santé, Informatique, Z-Score Method
Mots-clés Pascal anglais : Database management system, Comparative study, Methodology, Costs, Specific identification, Disease, Statistical analysis, Human, Public health organization, Health economy, Computer science
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0051838
Code Inist : 002B30A04B. Création : 14/05/1998.