Time is an essential concept in the practice of medicine. Clarity about the relationship of patient condition and interventions and exposures is the mechanism by which hypotheses are generated regarding causality. Additionally, this is the means by which the efficacy of interventions aimed at stabilizing patients are assessed. Imprecision in time has both clinical and medicolegal implications. In this study we describe the results of an evaluation of precision around the concept of time in our Critical Care Unit. We propose a scheme that can be used to classify these errors and describe how many sources of imprecision in time in medical data have contributions from more than one category of error.
