http://manuals.pqstat.pl/ 2026-05-14T16:50:25+00:00 http://manuals.pqstat.pl/ http://manuals.pqstat.pl/lib/tpl/dokuwiki/images/favicon.ico text/html 2022-02-15T19:35:39+00:00 Anonymous (anonymous@undisclosed.example.com) http://manuals.pqstat.pl/en:statpqpl:wielowympl:logistpl:orpl The Odds Ratio Individual Odds Ratio On the basis of many coefficients, for each independent variable in the model an easily interpreted measure is estimated, i.e. the individual Odds Ratio: The received Odds Ratio expresses the change of the odds for the occurrence of the distinguished value (1) when the independent variable grows by 1 unit. The result is corrected with the remaining independent variables in the model so that it is assumed that they remain at a stable level while the studie… text/html 2023-03-31T19:04:42+00:00 Anonymous (anonymous@undisclosed.example.com) http://manuals.pqstat.pl/en:statpqpl:wielowympl:logistpl:pred Model-based prediction and test set validation Validation Validation of a model is a check of its quality. It is first performed on the data on which the model was built (the so-called training data set), that is, it is returned in a report describing the resulting model. To be able to judge with greater certainty how suitable the model is for forecasting new data, an important part of the validation is to apply the model to data that were not used in the model estimation. If the summary ba… text/html 2023-03-31T19:08:23+00:00 Anonymous (anonymous@undisclosed.example.com) http://manuals.pqstat.pl/en:statpqpl:wielowympl:logistpl:przykl Examples for logistic regression EXAMPLE (anomaly.pqs file) Studies have been conducted for the purpose of identifying the risk factors for a certain rare congenital anomaly in children. 395 mothers of children with that anomaly and 375 of healthy children have participated in that study. The gathered data are: address of residence, child's sex, child's weight at birth, mother's age, number of pregnancy, previous spontaneous abortions, respiratory tract infections, smoking, mother's education… text/html 2022-02-15T20:05:38+00:00 Anonymous (anonymous@undisclosed.example.com) http://manuals.pqstat.pl/en:statpqpl:wielowympl:logistpl:werpl Model verification * Statistical significance of particular variables in the model (significance of the Odds Ratio) On the basis of the coefficient and its error of estimation we can infer if the independent variable for which the coefficient was estimated has a significant effect on the dependent variable. For that purpose we use text/html 2022-02-15T20:11:13+00:00 Anonymous (anonymous@undisclosed.example.com) http://manuals.pqstat.pl/en:statpqpl:wielowympl:logistpl:wykresy Graphs in logistic regression * Odds Ratio with confidence interval -- is a graph showing the OR along with the 95 percent confidence interval for the score of each variable returned in the constructed model. For categorical variables, the line at level 1 indicates the odds ratio value for the reference category.