Significant cost savings and similar patient outcomes associated with early discharge following total knee arthroplasty

Discussion

We found significantly lower in-hospital costs with a postoperative day 1 discharge protocol than with the standard LOS following TKA, with no difference in patient-reported outcomes 1 year following surgery. At our institution, the standard of care LOS is an average of 2–3 days, which is even lower than the suggested provincial guideline of 4 days,4 therefore even greater cost savings may be realized with an early discharge protocol at other institutions.

Previous studies have evaluated the impact of reduced LOS on clinical outcomes and found that an earlier discharge is a feasible alternative to traditional inpatient TKA. For example, Raphael and colleagues5 evaluated a reduced LOS protocol (average length of stay of 47 h v. 116 h) and found no increase in complication or readmission rates. Similarly, Kolisek and colleagues6 compared patients who underwent TKA with an accelerated pathway (discharged within 23 h of surgery) to those who followed a standard inpatient protocol with a mean hospital stay of 2–4 days. They found no differences in perioperative complications, returns to hospital or Knee Society scores at a mean follow up of 24 months. Finally, a retrospective analysis of more than 50 000 total hip arthroplasties (THA) and TKAs found no differences in 30-day major complications or readmissions among patients with a 0–2 day hospital stay compared with those discharged on postoperative day 3 or 4.7 Although these findings are encouraging, the validity and generalizability of the results are limited by the retrospective nature of the studies and the carefully selected patient cohorts. Furthermore, these studies did not evaluate the economic impact of those results.

Considering the large and increasing number of TKAs performed annually, there is a need to evaluate the economic efficiency of current models of care. This has led some clinicians to perform arthroplasty as an outpatient procedure, where eligible patients are discharged home the same day as their surgery. Eliminating the overnight hospital stay is a novel opportunity to improve economic efficiency, yet large, high-quality, evidenced-based comparisons to traditional inpatient models are lacking.

A retrospective study by Lovald and colleagues8 estimated that outpatient TKA compared with an inpatient stay of 3–4 days resulted in cost savings of $8527. Huang and colleagues9 conducted a case–control study comparing the costs among 20 patients who were discharged the same day of surgery to 20 inpatients who underwent TKA. They found that the same-day discharge resulted in a median cost savings of approximately 30%. At 1 year postoperative, there were no major complications and no returns to hospital or readmissions for either group.9

Although these results are encouraging, future study is warranted to determine if similar results can be found in a randomized controlled trial adequately powered to detect differences in adverse event rates between groups, incorporating a full economic evaluation. Importantly, evaluation of barriers to implementation of outpatient pathways is necessary, as an abrupt change in practice to current TKA care pathways may be hindered by changes to both clinical practice and current funding models. For example, in Ontario, although physicians are reimbursed the same amount for outpatient and inpatient procedures, outpatient TKA is not incorporated into current Quality-Based Procedures (QBP) indicators, therefore hospitals are not compensated for outpatient arthroplasty unless covered under another global funding budget other than the QBP.3 Furthermore, postoperative physical therapy is covered by public funding only following an overnight stay in hospital.10 As part of the transition of care, first moving to a postoperative day 1 discharge may enable a smoother, more appropriate transition to outpatient care, allowing sufficient evidence to be generated to inform future funding models and care pathways.

The transition to implementing outpatient THA has followed a similar pathway. Prior studies have reported patient-reported, clinical and cost outcomes following outpatient THA as well as an evaluation of barriers encountered with the accelerated discharge protocols.11,12 Similarly, the transition of care to reduced LOS in TKA requires changes in practice among all health care providers involved in the care of the patient. This includes changes in surgical approach, such as greater care of soft tissue management, decreased blood loss and reduced tourniquet time. It also may require new anesthesia techniques.

Although our initial intention of the early discharge protocol in the present study was to enable an LOS shorter than 24 hours, the average LOS of patients in the early discharge group was longer than 24 hours. The most common reason for a delay in discharge was complications of the intra-articular catheters used to deliver analgesics. The mode of failure was leakage, demonstrating that newer anesthesia techniques allow pain control issues to be addressed, but may introduce additional complications that affect time to discharge. Our experience highlights several aspects to consider and address when implementing and evaluating an early discharge protocol: the learning curve associated with the changes in the care pathway, effective communication strategies among the entire care team, patient satisfaction with postoperative pain control, and evaluation of the patient and caregiver experience with the new care pathway.