Factors Predicting Overnight Admission after Same-Day Mastectomy Protocol and Associated Financial Implications

Same-day mastectomy (SDM) protocols have been shown to be safe, and their use increased up to 4-fold compared with prepandemic rates. We sought to identify factors that predict overnight patient admission and evaluate the associated cost of care.

Patients undergoing mastectomy from March 2020 to April 2022 were analyzed. Patient demographics, tumor characteristics, operative details, perioperative factors, 30-day complication, fixed and variable cost, and contribution margin were compared between those who underwent SDM vs those who required overnight admission after mastectomy (OAM).

Of a total of 183 patients with planned SDM, 104 (57%) had SDM and 79 (43%) had OAM. Both groups had similar demographic, tumor, and operative characteristics. Patients who required OAM were more likely to be preoperative opioid users (p = 0.002), have higher American Society of Anesthesiology class (p = 0.028), and more likely to have procedure start time (PST) after 12:00 pm (49% vs 33%, p = 0.033). The rates of 30-day unplanned postoperative events were similar between SDM and OAM. Preoperative opioid user (odds ratio [OR] 3.62, 95% CI 1.56 to 8.40), postanesthesia care unit length of stay greater than 1 hour (OR 1.17, 95% CI 1.01 to 1.37), and PST after 12:00 pm (OR 2.56, 95% CI 1.19 to 5.51) were independent predictors of OAM on multivariate analysis. Both fixed ($5,545 vs $4,909, p = 0.03) and variable costs ($6,426 vs $4,909, p = 0.03) were higher for OAM compared with SDM. Contribution margin was not significantly different between the 2 groups (-$431 SDM vs -$734 OAM, p = 0.46).

Preoperative opioid use, American Society of Anesthesiology class, longer postanesthesia care unit length of stay, and PST after noon predict a higher likelihood of admission after planned SDM. OAM translated to higher cost but not to decreased profit for the hospital.