Statistics in medicine
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Statistics in medicine · Dec 2002
Comparative StudyUse of the mean, hot deck and multiple imputation techniques to predict outcome in intensive care unit patients in Colombia.
A cohort of intensive care unit (ICU) patients in 20 Colombian ICUs is used to describe the application of three imputation techniques: single, hot deck and multiple imputation. These strategies were used to impute the missing data in the variables used to construct APACHE II scores, a scoring system for the ICU patients that provides an unbiased standardized estimate of the probability of hospital death. ⋯ The area under the receiver operating characteristic (ROC) curve was used to compare imputation strategies with respect to predictive power. While statistically significant differences were found for the area under the ROC curve, these differences were not clinically significant.
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Statistics in medicine · Dec 2002
Modelling tooth emergence data based on multivariate interval-censored data.
Studies on emergence of (permanent) teeth are published regularly in the dental literature. Besides descriptive statistics (mean or median values) on emergence times, comparisons between boys and girls are of interest. Gender comparisons are intersubject analyses, but also intrasubject questions, like 'Is there a left-right symmetry with respect to the mean (median) emergence times?' are of interest. ⋯ We will extend a GEE-type test proposed by Huster et al. for bivariate right-censored data to the multivariate setting with interval-censored data. Central to our paper is to provide appropriate statistical models to resolve some dental questions on emergence. The analyses are based on data from the longitudinal Signal-Tandmobiel study.