SYNCHRONIZATION OF TIMEPIECES TO THE ATOMIC CLOCK IN AN URBAN EMERGENCY MEDICAL-SERVICES SYSTEM

Study objective: Erroneous time documentation of emergency treatment c aused by the variation in the accuracy of timepieces has profound medi cal, medicolegal, and research consequences. The purpose of this study was to confirm the variation of critical timepiece settings in an urb an emergency care system noted in previous studies and to implement an d monitor the results of a prospective program to improve time synchro nization. Methods: Timepieces (n=393) used by firefighters, paramedics , and emergency physicians and nurses were randomly sampled immediatel y before and at two time intervals (1 and 4 months) after attempted sy nchronization to the US atomic clock standard. The setting on each tim epiece was compared with the atomic clock. From the data, a mathematic al simulation estimated the number of time-related documentation error s that would occur in 2,500 simulated cardiac arrest cases using timep ieces with accuracy similar to those found in the EMS system before an d after attempted synchronization. Results: Before attempted synchroni zation, the timepieces had a mean error of 2.0 (95% confidence interva l 1.8 to 2.3) minutes. One month after attempted synchronization, the mean error decreased significantly to .9 (.8 to 1.1) minute. However, it increased to 1.7 (1.5 to 1.9) minutes within 4 months. Mathematical simulation before attempted synchronization predicted that 93% of car diac arrest cases would contain a documentation error of 2 minutes or more and that 41% of cases would contain a documentation error of 5 mi nutes or more. Attempted synchronization cut the 2 minute documentatio n error rate in half and reduced the 5-minute documentation error rate by three fourths. However, the error rates were predicted to return t o baseline 4 months after attempted synchronization. Conclusion: Emerg ency medical timepieces are often inaccurate, making it difficult to r econstruct events for medical, medicolegal, or research purposes. Comm unity synchronization of timepieces to the atomic clock can reduce the problem significantly, but the effects of a one-time attempted synchr onization event are short-lived.