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Context: Patient length of hospital stay (LOS) is an important measure of timeliness and efficiency in healthcare quality studies.
Objective: Because conclusions drawn about LOS may be influenced by assumptions of variable distribution, we sought to determine the quality of LOS data analysis in published pediatric clinical studies.
Study Selection: Articles from PubMed were included if they were of pediatric clinical studies published in English for a one year period of time between 6/1/2009 and 5/31/2010 where LOS was an outcome variable.
Data Extraction: The reported statistical approach was extracted from published manuscripts by 2 independent reviewers and included hospital LOS: distribution, measures of central tendency, and methods of statistical comparisons.
Results: Of 795 identified studies, 214 were included: only 33 reported LOS distribution of which 5 used the incorrect measure of central tendency. One hundred and two studies reported LOS means, 64 reported medians, and 22 reported both means and medians. Of 142 comparative studies, 61 used non-parametric methods, 53 parametric methods, 1 used both parametric and non-parametric methods, 7 transformed the variable, 18 did not specify, and 2 were missing.
Conclusions: Although used frequently as a measure of healthcare outcomes, there is wide variation in the statistical approach and reporting of LOS. We recommend that, at a minimum, investigators should follow the International Committee of Medical Journal Editors Uniform Requirements for Manuscripts Submitted to Biomedical Journals reporting of statistical data. Furthermore, investigators should evaluate, report, and use LOS distributions to inform LOS analyses.
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