Background Printed handoff documents are nearly universally present in the pockets of providers taking inhouse call. They are frequently used to answer clinical questions. However, the static nature of printed documents makes it likely that information will quickly become inaccurate as a result of ongoing management. This increases the potential for medical errors, especially in clinical services which rely heavily on printed documents for ongoing patient management.

Objective To measure the average time to potential inaccuracy, represented as the ‘half-life’ of printed handoff documents.

Design, setting, participants Cross-sectional analysis of 100 adult inpatients during a single 24 h period at an academic medical centre in 2014.

Main outcome and measure The half-life was defined as the time at which half of the patients would be expected to have inaccurate information on a printed handoff document, based on review of orders which populate data fields on these printed handoff documents.

Results In our sample, the half-life was 6 h on the 12 h night shift and 3.3 h on the day shift. We identified at least on change within the 24 h period for 92% of patients. Most changes (90% n=1411) were medication-related, but the overall distribution of order types was significantly different between day and night (p=0.002).

Conclusions and relevance The accuracy of printed handoff documents quickly deteriorated over the course of a physician shift. Based on this decay rate, a typical physician getting sign-out on 20 patients overnight can safely assume that the data for 10 of them will be inaccurate or outdated in 6 h and that it will be inaccurate on another two by the morning.