Heterogeneity between studies indicates that the Morse Falls Scale and STRATIFY may still be useful in particular setting s , but that widespread adoption of either is unlikely to generate benefits significantly greater than that of nursing staff clinical judgment
INTRODUCTION Fall risk screening tools are frequently used as a part of falls prevention programs in hospitals .
Design -related bias in evaluations of tool predictive accuracy could lead to overoptimistic results , which would then contribute to program failure in practice .
Internal validation of predictive models: efficiency of some procedures for logistic regression analysis.
The performance of a predictive model is overestimated when simply determined on the sample of subjects that was used to construct the model . Several internal validation methods are available that aim to provide a more accurate estimate of model performance in new subjects . We evaluated several variants of split- sample , cross-validation and bootstrapping methods with a logistic regression model that included eight predictors for  30-day mortality after an acute myocardial infa rct ion . R and om sample s with a size between n = 572 and n = 9165 were drawn from a large data set ( GUSTO-I ; n = 40,830 ; 2851 deaths ) to reflect modeling in data sets with between 5 and 80 events per variable . Independent performance was determined on the remaining subjects . Performance measures included discriminative ability , calibration and overall accuracy . We found that split- sample analyses gave overly pessimistic estimates of performance , with large variability . Cross-validation on 10 % of the sample had low bias and low variability , but was not suitable for all performance measures . Internal validity could best be estimated with bootstrapping , which provided stable estimates with low bias . We conclude that split- sample validation is inefficient , and recommend bootstrapping for estimation of internal validity of a predictive logistic regression model
Heterogeneity between studies indicates that the Morse Falls Scale and STRATIFY may still be useful in particular setting s , but that widespread adoption of either is unlikely to generate benefits significantly greater than that of nursing staff clinical judgment
INTRODUCTION Fall risk screening tools are frequently used as a part of falls prevention programs in hospitals .
Design -related bias in evaluations of tool predictive accuracy could lead to overoptimistic results , which would then contribute to program failure in practice .