DOES ANYBODY REALLY KNOW WHAT TIME IT IS - DOES ANYBODY REALLY CARE

Study objective: To evaluate the difference among time sources in an e mergency medical system. Design: Prospective; comparison to a criterio n standard. Setting: Five emergency departments and three emergency me dical services systems in Indianapolis, Indiana. Interventions: Coordi nated Universal Time (UTC), generated by the atomic clock in Boulder, Colorado, and broadcast by the US Commerce Department's National Insti tute of Standards and Technology, was used as the time standard. The i nvestigators, on a single day, made unannounced visits to the five EDs and the ambulances and fire stations in the three emergency medical s ervices systems. The times displayed on all time sources at each locat ion were recorded. The accuracy to the second of each time source comp ared to UTC was calculated. Results: Three time sources were excluded (two defibrillator clocks and one ED wall clock that varied more than three hours from UTC). Of the 152 time sources, 72 had analog displays , 74 digital, three both, and three other. The average absolute differ ence from UTC was 1 minute 45 seconds (SEM, 9 seconds) with a range of 12 minutes 34 seconds slow to 7 minutes 7 seconds fast. Thus, two tim epieces could have varied by as much as 19 minutes 41 seconds. Compare d to UTC, 47 timepieces (31%) were slow, 100 (66%) were fast, and five (3%) were accurate to the second. Fifty-five percent of the time sour ces varied one minute or more from UTC. Conclusion: Time sources in th is health care system varied considerably. Time recording in medicine could be made more precise by synchronizing medical clocks to UTC, usi ng computers to automatically ''time stamp'' data entries and using on ly digital time sources with second displays.