Patient Characteristics and Surgical Start Time Affect Length of Stay Following Anterior Total Hip Arthroplasty.

Background: Currently, no consensus exists for selection criteria of appropriate candidates for outpatient total hip arthroplasty (THA). This study evaluates patient characteristics associated with same-day discharge, examined surgical start time's effect on rates of same-day discharge, and compares readmission and reoperation rates between groups.

Methods: All patients who underwent a THA by one surgeon at a single quaternary care hospital between February 2016 and May 2018 were captured. All patients were given the option for same-day discharge. Patient characteristics and perioperative variables were analyzed.

Results: A total of 429 patients met inclusion criteria, 153 (36%) were discharged on the day of surgery. In a multivariate analysis, age (P = .000), multiple comorbidities (P = .004), and start time remained statistically significant (P = .000). Patients with start times prior to 9 AM had odds ratio of 11.56 of being discharged same day when compared to those with start times after 12 PM. Patients discharged the day of surgery were less likely to have a 90-day emergency room visit (P = .010), a readmission within 30 days (P = .001) or 90 days (P = .000), or a reoperation (0 vs 14, P = .003).

Conclusion: Same-day discharge following THA is safe and feasible. Patient's age and number of comorbidities should be considered when developing selection criteria for same-day discharge programs. Patients selected for same-day discharge should receive earlier operating room start times.