Primary total joint arthroplasty (TJA) of the hip and of the knee are common and effective procedures for improving pain and function in patients with arthritis. Recent literature estimates that more than 7 million Americans are currently living with a TJA.1 National registries estimate that more than 1 million total knee and total hip replacements are performed annually in the United States.1 As the baby boomers continue to age, the demand for TJA is expected to continue to increase. Kurtz et al2 predict that by 2030 there will be 572,000 total hip arthroplasties (THAs) and 3.48 million total knee arthroplasties (TKAs) performed annually in the United States alone.
In recent years, there has been a shift toward outpatient surgery and postoperative day 1 discharges. However, because of advanced age, lack of family support, or medical conditions, patients still require additional postoperative care at an extended care facility (ECF). At the authors' institution, approximately 18% of TJA patients require discharge to an ECF. Discharge to an ECF requires a significant amount of planning and communication between physicians, care managers, physical therapists, insurance companies, and facility staff. Medicare and many insurance providers require 3 nights of hospitalization prior to discharge to an ECF for postoperative patients.3 In the current authors' experience, patients will frequently have met physical therapy milestones and are stable for discharge but have delays due to non-medical issues, including insurance authorization and facility acceptance policies (eg, not accepting new patients on the weekend or on Sunday). These delays increase health care costs, decrease patient satisfaction, and prolong patient exposure to hospital-acquired diseases.
The purpose of this study was to evaluate whether surgical day of the week impacts the hospital length of stay (LOS) for TKA and THA, for patients discharged to an ECF, within a single, high-volume hospital. The authors hypothesized that patients who have surgery on Wednesday or Thursday, and therefore anticipated discharge days of Saturday or Sunday, are more likely to have delays in discharge.
Materials and Methods
After institutional review board approval was obtained, a TJA database from a single hospital was used to identify all patients who underwent elective primary TKA and primary THA between January 2013 and December 2016. Only patients who were discharged to an ECF and had surgery Monday through Friday were included in this study. Patients were excluded if they were younger than 50 years, had a revision procedure, had an emergent case, had a simultaneous bilateral procedure, or were discharged home or to inpatient rehabilitation. Additionally, patients discharged after postoperative day 7 were excluded to reduce outliers secondary to extended stay for medical complications. A total of 2184 patients met inclusion criteria and were divided into 5 groups based on the day of the week of surgery. Groups were compared based on demographic factors to rule out any confounders and based on hospital LOS.
A one-way analysis of variance test was used to assess differences in normal, continuous variables based on the day of surgery. A Kruskal–Wallis test was used to assess differences in nonparametric variables across days of the week, with a Dunn–Bonferroni test used for pairwise comparisons. A chi-square test was used to analyze differences in categorical variables. Additionally, a two-way analysis of variance was used to assess whether there was a significant difference in LOS based on the interaction between surgical day and procedure type (TKA vs THA). P<.05 was considered significant for all tests.
In the population of 2184 patients, there was no statistically significant difference in age (P=.120), sex (P=.959), body mass index (P=.472), American Society of Anesthesiologists score (P=.256), or procedure (TKA vs THA, P=.395) between the groups based on the day of the week of surgery (Table 1). The LOS varied significantly by day of the week (P<.001; Figure). Thursday had the longest LOS (mean, 3.56±0.84 days) and varied significantly from every other day of the week (P<.001). Tuesday had the shortest LOS (mean, 3.25±0.70 days) and differed significantly from Thursday and Friday (P<.05).
Patient Demographics Stratified by Day of the Week
Mean length of stay based on surgical day of the week for patients being discharged to an extended care facility. Error bars represent the 95% confidence interval. Thursday varied significantly from every other day of the week (*), and Tuesday varied significantly from Thursday and Friday (+).
Patients who had surgery on Thursday had the lowest percentage of discharges on postoperative day (POD) 3 (59.1%) and the highest percentage of discharges on POD 4 (27.8%), compared with all other days (Table 2). Patients who had surgery on Tuesday had the highest percentage of discharges on POD 3 (83.2%). Furthermore, of all patients in the cohort who were discharged on POD 4, the greatest percentage had surgery on Thursday (38.0%). There was no significant difference in LOS based on the interaction between procedure day of the week and procedure type (TKA vs THA) (P=.141).
Percentage of Discharges on Postoperative Days 1 Through 7 Based on Day of Surgery and Procedure
Many factors potentially affecting LOS have been evaluated and addressed, but only recently has hospital LOS secondary to surgical day of the week been discussed.4–8 To the current authors' knowledge, this is the first study to evaluate LOS following TKA and THA in patients discharged to an ECF based on the day of the week of surgery and to include Monday through Friday. The authors found that patients who had surgery on Thursday had a greater LOS than patients who had surgery on any other day of the week. This correlates with an anticipated discharge day of Sunday.
A study by Muppavarapu et al5 examined LOS based on day of surgery among 547 patients after TKA and THA, regardless of discharge disposition. They found that patients had a shorter LOS if surgery was performed on Monday or Tuesday when compared with Thursday or Friday. Contrary to the current authors' findings, they did not find a statistically significant difference in LOS based on the day of surgery when examining only the patients who were discharged to an ECF; however, their sample was smaller and their study may not have been powered to detect a difference.
In 2016, Keswani et al6 examined whether surgery in the beginning vs the end of the week impacted hospital LOS for 580 THA patients of a single surgeon. They grouped patients who had surgery Monday or Tuesday vs Thursday or Friday, finding that patients with surgery later in the week had a significantly longer length of hospitalization. They also found that procedures beginning later than 2:00 pm had increased LOS. Newman et al4 similarly grouped patients and found that the Monday/Tuesday group had shorter hospitalizations prior to discharge in a large study.
Although hospital LOS following primary TJA is decreasing,9 it continues to be one of the strongest factors associated with total cost.10,11 Improvements in postoperative pain management, early mobilization, fast-track rehabilitation, and improved preoperative patient education and clinical pathways have all contributed to a decrease in LOS.12–15 In the current authors' experience, discharge to an ECF, as compared with discharge to home, can increase hospital LOS. Comorbidities, American Society of Anesthesiologists class, insurance type, age, and female sex have all been evaluated as predictors for ECF discharge and increased hospital LOS.16–18 Screening guidelines to predict patients requiring postoperative ECF stays have been proposed but are not routinely used.19,20 Given the results of this study and other similar studies, hospital LOS and total cost could potentially be reduced by being better able to predict those patients requiring ECF and scheduling the surgical day of the week accordingly. When discharge to an ECF is known in advance, preferentially scheduling those patients early in the week is an easy modification that could save considerable money.
Multiple factors likely contribute to the correlation between day of surgery and length of hospitalization prior to discharge to an ECF. Principally, nonmedical reasons such as facilities' restrictions on weekend acceptance of new patients, decreased weekend insurance approval because fewer employees are working, and fewer on-site care managers facilitating the discharge can all lead to prolonged hospitalization for patients with anticipated weekend discharges. Also, many hospitals function with a limited physical therapy team on the weekend, which can delay patients' progress and discharge.
This study is unique in that the authors included only patients discharged to an ECF and evaluated surgeries performed on each weekday (Monday through Friday) individually. Strengths of this study included a relatively larger patient population compared with previous studies, without the confounding effect of home vs ECF discharges.
However, this study is not without limitations. The authors used a retrospective chart review, which is an inherently weaker design than a prospective, randomized study with multivariate analysis. However, surgical day randomization among several private practice surgeons for 2184 patients would not have been feasible. Additionally, this study was conducted at a single hospital, with inherent regional or institutional biases. A third limitation is that the cohort included both THA and TKA patients, which could be a potential confounding factor; however, the authors did not find statistically significant differences in LOS between the THA and TKA patients. Furthermore, surgical approach was not evaluated in this study and is a potential confounding factor if not equally distributed among the specific days of the week. Finally, a multivariate analysis of patient comorbidities was not conducted.
Patients discharged to an ECF after primary TKA and THA have an increased mean hospital LOS when their surgery falls on a Thursday. This correlates with their anticipated discharge date on a weekend. The authors recommend preferentially scheduling patients with planned postoperative discharge to an ECF for surgery on Tuesday and avoiding surgery on Thursday.
- Maradit Kremers H, Larson DR, Crowson CS, et al. Prevalence of total hip and knee replacement in the United States. J Bone Joint Surg Am. 2015; 97 (17):1386–1397. doi:10.2106/JBJS.N.01141 [CrossRef]
- Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007; 89(4):780–785.
- Lipsitz LA. The 3-night hospital stay and Medicare coverage for skilled nursing care. JAMA. 2013; 310(14):1441–1442. doi:10.1001/jama.2013.254845 [CrossRef]
- Newman JM, Szubski CR, Barsoum WK, Higuera CA, Molloy RM, Murray TG. Day of surgery affects length of stay and charges in primary total hip and knee arthroplasty. J Arthroplasty. 2017; 32(1):11–15. doi:10.1016/j.arth.2016.06.032 [CrossRef]
- Muppavarapu RC, Chaurasia AR, Schwarzkopf R, Matzkin EG, Cassidy CC, Smith EL. Total joint arthroplasty surgery: does day of surgery matter?J Arthroplasty. 2014; 29(10):1943–1945. doi:10.1016/j.arth.2014.06.004 [CrossRef]
- Keswani A, Beck C, Meier KM, Fields A, Bronson MJ, Moucha CS. Day of surgery and surgical start time affect hospital length of stay after total hip arthroplasty. J Arthroplasty. 2016; 31(11):2426–2431. doi:10.1016/j.arth.2016.04.013 [CrossRef]
- Husted H, Holm G, Jacobsen S. Predictors of length of stay and patient satisfaction after hip and knee replacement surgery: fast-track experience in 712 patients. Acta Orthop. 2008; 79(2):168–173. doi:10.1080/17453670710014941 [CrossRef]
- Mathijssen NM, Verburg H, van Leeuwen CC, Molenaar TL, Hannink G. Factors influencing length of hospital stay after primary total knee arthroplasty in a fast-track setting. Knee Surg Sports Traumatol Arthrosc. 2016; 24(8):2692–2696. doi:10.1007/s00167-015-3932-x [CrossRef]
- Vorhies JS, Wang Y, Herndon J, Maloney WJ, Huddleston JI. Readmission and length of stay after total hip arthroplasty in a national Medicare sample. J Arthroplasty. 2011; 26(6) (suppl):119–123. doi:10.1016/j.arth.2011.04.036 [CrossRef]
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- Culler SD, Jevsevar DS, Shea KG, Wright KK, Simon AW. The incremental hospital cost and length-of-stay associated with treating adverse events among Medicare beneficiaries undergoing TKA. J Arthroplasty. 2015; 30(1):19–25. doi:10.1016/j.arth.2014.08.023 [CrossRef]
- Peters CL, Shirley B, Erickson J. The effect of a new multimodal perioperative anesthetic regimen on postoperative pain, side effects, rehabilitation, and length of hospital stay after total joint arthroplasty. J Arthroplasty. 2006; 21(6)(suppl 2):132–138. doi:10.1016/j.arth.2006.04.017 [CrossRef]
- Husted H, Hansen HC, Holm G, et al. What determines length of stay after total hip and knee arthroplasty? A nationwide study in Denmark. Arch Orthop Trauma Surg. 2010; 130(2):263–268. doi:10.1007/s00402-009-0940-7 [CrossRef]
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- Bozic KJ, Wagie A, Naessens JM, Berry DJ, Rubash HE. Predictors of discharge to an inpatient extended care facility after total hip or knee arthroplasty. J Arthroplasty. 2006; 21(6) (suppl 2):151–156. doi:10.1016/j.arth.2006.04.015 [CrossRef]
- Sikora-Klak J, Zarling B, Bergum C, Flynn JC, Markel DC. The effect of comorbidities on discharge disposition and readmission for total joint arthroplasty patients. J Arthroplasty. 2017; 32(5):1414–1417. doi:10.1016/j.arth.2016.11.035 [CrossRef]
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Patient Demographics Stratified by Day of the Week
|Characteristic||Day of the Week||P|
|Age, mean±SD, y||72.9±8.5||71.7±8.4||72.7±8.7||72.9±8.9||72.9±9.3||.120|
| Female||237 (75%)||400 (76%)||354 (77%)||377 (77%)||305 (77%)|
| Male||78 (25%)||125 (24%)||103 (23%)||112 (23%)||93 (23%)|
|Body mass index, mean±SD, kg/m2||30.77±6.63||30.87±6.48||31.14±6.58||31.54±7.19||31.20±6.83||.472|
|American Society of Anesthesiologists score, mean±SD||2.5±0.5||2.5±0.5||2.5±0.6||2.6±0.7||2.6±0.5||.256|
| Total hip arthroplasty||120 (38%)||203 (39%)||180 (39%)||177 (36%)||170 (43%)|
| Total knee arthroplasty||195 (62%)||322 (61%)||277 (61%)||312 (64%)||228 (57%)|
Percentage of Discharges on Postoperative Days 1 Through 7 Based on Day of Surgery and Procedure
|Discharge Day/Procedure||Day of Surgery|