Comparisons of unscheduled absences among categories of anesthesia practitioners, including anesthesiologists, nurse anesthetists, and anesthesia residents

BACKGROUND: An “unscheduled absence” refers to an occurrence when an employee does not appear for work and the absence was without advance approval by an authorized supervisor. Recently we estimated the prevalence of unscheduled absences in a cohort of certified registered nurse anesthetists at the University of Miami. We performed a historical cohort study for all types of anesthesia practitioners at the University of Iowa. METHODS: Two-years of person-assignment days were studied. The total population was 62,951 regular operating room days among 293 people. There were 56,437 days among 203 practitioners with multiple workdays over multiple quarters. RESULTS: In the total population, the 91 nurse anesthetists had 1.48% person-days with an unscheduled absence, comparable to the 1.74% from University of Miami. Most unscheduled absences (99% lower confidence limit 80.1%) resulted in the person being absent from an operating room clinical assignment for just 1 day. Compared with nurse anesthetists, residents and fellows had proportionately fewer unscheduled absences (odds ratio 0.24 [0.13-0.45], P<.0001), as did anesthesiologists (0.49 [0.30-0.79], P=.0002). Among all practitioners, Mondays, Fridays, and days adjacent to holidays had significantly more unscheduled absences than Tuesdays, Wednesdays, and Thursdays (1.45 [1.19-1.76], P<.0001). CONCLUSIONS: To have an adequate daily workforce, anesthesia clinical directors need to estimate the daily expected percentage of assigned anesthesia practitioners who will be absent. Potential inter-group differences should be considered. We provide a worked example showing how to use the results to decide numbers of practitioners to plan daily.