Rate of undesirable events at beginning of academic year: retrospective cohort study

Objective To determine whether an increase in the rate of undesirable events occurs after care provided by trainees at the beginning of the academic year.Design Retrospective cohort study using administrative and patient record data.Setting University affiliated hospital in Melbourne, Australia.Participants 19 560 patients having an anaesthetic procedure carried out by first to fifth year trainees starting work for the first time at the hospital over a period of five years (1995-2000).Main outcome measures Absolute event rates, absolute rate reduction, and rate ratios of undesirable events.Results The rate of undesirable events was higher at the beginning of the academic year compared with the rest of the year (absolute event rate 137 v 107 per 1000 patient hours, relative rate reduction 28%, P