[Abnormally broad confidence intervals in logistic regression: interpretation of results of statistical programs].
This study describes the behavior of eight statistical programs (BMDP, EGRET, JMP, SAS, SPSS, STATA, STATISTIX, and SYSTAT) when performing a logistic regression with a simulated data set that contains a numerical problem created by the presence of a cell value equal to zero. The programs respond in different ways to this problem. Most of them give a warning, although many simultaneously present incorrect results, among which are confidence intervals that tend toward infinity. Such results can mislead the user. Various guidelines are offered for detecting these problems in actual analyses, and users are reminded of the importance of critical interpretation of the results of statistical programs.
de Irala
J
J
Universidad de Córdoba, Facultad de Medicina, Departamento de Medicina Preventiva y Salud Pública, España.
Fernandez-Crehuet Navajas
R
R
Serrano del Castillo
A
A
D016001:Confidence Intervals; D016015:Logistic Models; D012984:Software; D013223:Statistics as Topic
Intervalos de confianza anormalmente amplios en regresión logística: interpretación de resultados de programas estadísticos.