In the short-stay surgery setting, where patients remain in hospital for a single overnight at most, it is unclear as to whether postoperative length of stay is a good surrogate for assessing rapidity of recovery. We hypothesized that length of stay would be a function of time of surgery and would be a poorer marker of recovery than time of discharge.
A cohort of 891 mastectomy and 538 prostatectomy patients had a planned single overnight stay after surgery at an ambulatory surgical hospital during 2016. The relationship between surgical start time and postoperative length of stay or discharge time was assessed.
For both mastectomy and prostatectomy patients, 75% of patients were discharged between 10 am and 12 noon and the median postoperative length of stay was 20 hours. There was a strong association between time of surgery and calculated length of stay. For mastectomies, having a surgery which begins at 6 pm vs 8 am results in an estimated decrease of 8.8 hours (95% CI, 8.3–9.3) in postoperative length of stay but only 1.2 hours (95% CI, 0.77–1.6) later time of discharge. For prostatectomies, the estimated difference is a decrease of 6.9 hours (95% CI, 6.4–7.4) for postoperative length of stay and 2.5 hours (95% CI, 2.0–3.0) later discharge time.
Postoperative length of stay is a poor outcome measure in a short-stay setting. When assessing rapidity of recovery for single overnight stay patients, we advocate the use of discharge time with adjustment for surgery start time. The effect of surgery start time on both postoperative length of stay and discharge time should be investigated to ascertain which is best to assess rapidity of recovery in other ambulatory care settings where recovery involves a single overnight stay.