Total shoulder arthroplasty (TSA) procedures have doubled in the United States over the past ten years [1]. With approximately 70,000 surgeries each year, TSA has become the fastest growing total joint replacement procedure in the United States [1,2]. The number of procedures is expected to further increase given the aging population and the notable success of TSA procedures in restoring function and reducing pain [3,4]. TSA procedures are used to treat various degenerative conditions of the shoulder common in older adult populations [4,5].

Facility utilization constitutes an additional modifiable aspect of overall cost for these procedures. Minimizing hospital length of stay has the potential to greatly reduce health care spending. Same-day discharge, defined as discharge from the hospital within 24 h of surgery, has been shown to be safe for joint arthroplasty. The objective of the present study was to evaluate demographic and clinical factors associated with same-day discharge among adult patients who underwent shoulder arthroplasty (total and hemiarthroplasty) using the American College of Surgeons National Quality Improvement Program (ACS NSQIP) database. A secondary objective was to identify risk factors for 30-day unplanned hospital readmission. 

We conducted a retrospective cohort analysis of factors associated with same-day hospital discharge and 30-day hospital readmission after shoulder arthroplasty using patient data from a nationally validated surgical outcomes registry. The odds of same-day discharge was lower for every 10-year increase in age and for patients with a medical history of insulin dependent diabetes, poor functional status, COPD, CHF, bleeding disorder, or ASA class 3 or 4. However, in this study, the odds of same-day discharge was significantly increased for male patients. Patients with comorbidities were also more likely to experience unplanned hospital readmission. Although ambulatory surgery is well established and safe for knee and hip arthroplasty [7], further work is needed to define and understand the risk of adverse outcomes and benefits of ambulatory surgery for shoulder arthroplasty.

Although shoulder arthroplasty is less commonly performed than knee and hip arthroplasty, the demand is projected to increase [8]. The annual procedure volume growth rate of total shoulder arthroplasty and hemiarthroplasty was 9.4% and 5.4%, respectively [8]. From 1993 to 2007, there has been roughly a 2-fold reduction in postoperative hospital length of stay due to improvements in surgical technique and prosthetic design, preoperative patient education, use of intraoperative anesthetics allowing for rapid recovery, and postoperative multimodal analgesia. However, costs associated with shoulder arthroplasty have steadily increased [8–10]. Identifying factors and designing interventions mitigating barriers to cost control is therefore important.

In 2017, United States health care spending grew by 3.9% and comprises roughly 18% of annual spending [11]. Same-day discharge has been identified as a potential opportunity to lower costs while improving patient satisfaction and quality of care for joint arthroplasty [12]. The recent demand for ambulatory surgery may be due to escalating health care costs, and implementing same-day surgery discharged protocols with multidisciplinary care teams may be cost-effective. Same-day discharge is becoming common practice in many medical specialties across academic surgery centers and hospitals. Ambulatory TSA has increased in response to advances in multimodal pain management, patient screening parameters, and efforts to reduce costs due to inpatient admission. Cost benefit analyses estimate that outpatient procedures can lead to savings of thousands of dollars per patient and millions of dollars over the next ten years [13,14]. Previous studies of ACS NSQIP and single institution data have retrospectively examined predictors of morbidity with same day TSA procedures [13,15,16]. These factors, such as CHF, hematocrit < 38%, BMI, and depression, allow physicians to screen for suitable candidates, further decreasing morbidity post-operatively. Current studies have found no significant differences in the complication rates between same day discharge and inpatient procedures in appropriately screened patients [14].

We identified several comorbidities that were associated with a decrease in same-day discharge. Not surprisingly, patients with insulin-dependent diabetes mellitus, poor functional status, COPD, CHF, bleeding disorders, or higher ASA class were less likely to be discharged on the same day as the surgery. Sher and colleagues show a higher prevalence of impaired functional status, history of pulmonary and cardiac disease, stroke, and ASA class ≥ 3 among patients who were not eligible for same-day discharge following total knee or hip arthroplasty [12]. Similarly, Basques and colleagues report that diabetes mellitus and older age were shown to be associated with higher rates of 30-day readmission following same-day discharger for joint arthroplasty [17]. While many of these conditions are chronic, patients may benefit from preoperative optimization and postoperative multidisciplinary coordinated care pathways.

If patients are candidates for same-day discharge, early physical therapy has been shown to reduce readmission rates among patients undergoing total joint arthroplasty [18], and may be beneficial in this surgical population. Gogineni et al. [19] report no differences in complications rates among patients who underwent outpatient versus inpatient surgery after implementing structured care pathways involving surgeons, anesthesiologists, case management, rehabilitation services, home care companies, hospital administrators, and nursing leaders. Life expectancy has increased in the United States and consequently chronic diseases have become more prevalent. We must counteract the deleterious impact of these chronic conditions by standardizing preoperative care and mobilizing multidisciplinary health teams.

Joint arthroplasty is more common among women, who also experience worse health outcomes compared to men [20]. In this study, the odds of same-day discharge was 86% higher for men compared to women. While the causes of this disparity are currently undefined, possible explanations include higher comorbidity burden in women, worse functional status, or other sociodemographic features that worsen outcomes. Further work is needed to substantiate our findings and provide insight into other contributing factors, with the ultimate aim to identify modifiable factors that may improve health outcomes and reduce health care spending.

ACS NSQIP is an excellent database source for evaluating outcomes in ambulatory surgery. However, ACS NSQIP does not include important perioperative variables that would allow for a more detailed and informative study such as cost associated with same-day versus non-same day discharge, severity of preoperative comorbidities, prosthesis used, surgeon’s experience, hospital volume, intraoperative anesthetic agents delivered, intraoperative variables (i.e., case duration and estimated blood loss), and pain management strategies. This retrospective study has limitations that are inherent to retrospective studies that include but are not limited to misclassification bias and confounding. Fortunately, since ACS NSQIP prospectively collects data, the temporal relationship between preoperative and postoperative variables is not ambiguous. Additionally, ACS NSQIP has program demands that may limit the participation of smaller community hospitals.

In conclusion, this is the first study to evaluate factors associated with same-day discharge and unplanned readmission following shoulder arthroplasty. The results of this study show that preoperative comorbidities and advanced age reduce the odds of same-day discharge and increase the odds of unplanned readmission. Risk stratification, preoperative optimization, and coordinated care after surgery may help to safely implement standardized protocols for same-day discharge. Enhanced care pathways may be helpful for patients who are candidates for same-day discharge.