Predicting Day-Case Arthroplasty Outcomes

Which patient factors best predict success/failure of day-case arthroplasty?

Increased age, female sex (OR 1.63-4.22), high ASA classification, and multiple comorbidities (OR up to 3.9) are the primary predictors of day-case arthroplasty failure.

Abstract

Day‐case arthroplasty outcomes are influenced by clear patient factors. Studies report that increased age—which in over 20 analyses shows odds ratios from 1.01 to 4.16—and female sex—with odds ratios from 1.63 to 4.22 in more than 15 investigations—predict lower same‐day discharge success. A higher body mass index (supported in 10+ studies) and non‐white race (noted in 5+ studies) similarly relate to reduced success. In addition, clinical indicators such as an ASA classification of III or IV and a comorbidity burden of three or more conditions consistently predict failure, with odds ratios up to 3.9 and highly significant p‐values. Other conditions, including hypertension, diabetes, cardiovascular disease, and chronic obstructive pulmonary disease, are also cited as contributing to poor day‐case outcomes. Although a couple of studies flag younger age (<40) as a potential risk factor, this finding remains inconsistent.

Methods

We analyzed 40 sources from an initial pool of 500, using 8 screening criteria. Each paper was reviewed for 6 key aspects that mattered most to the research question.

• Papers identified with Elicit search
• n = 500
• Papers screened using: Study Setting, Patient Population - Age, Procedure Type, Clinical Context, Predictive Factors, Outcome Measures, Study Design, Study Focus
• n = 500
• Papers screened out
• n = 460
• Papers included for extraction
• n = 40

Paper search

Using your research question “Which patient factors best predict success/failure of day-case arthroplasty?”, we searched across over 126 million academic papers from the Semantic Scholar corpus. We retrieved the 500 papers most relevant to the query.

Screening

We screened in sources based on their abstracts that met these criteria:

• Study Setting: Does the study investigate outpatient/day-case/ambulatory arthroplasty procedures?
• Patient Population - Age: Does the study include only adult patients (≥18 years)?
• Procedure Type: Does the study examine primary (non-revision) hip, knee, shoulder, or ankle arthroplasty?
• Clinical Context: Does the study examine planned elective procedures (not emergency or trauma-related cases)?
• Predictive Factors: Does the study analyze patient-related predictive factors (such as age, BMI, comorbidities, or social support)?
• Outcome Measures: Does the study report specific outcomes related to success/failure of day-case surgery (such as same-day discharge, unplanned overnight stays, or 30-day readmissions)?
• Study Design: Is the study design either a prospective/retrospective cohort study, case-control study, RCT, or systematic review with 10 or more patients?
• Study Focus: Does the study include patient-related factors (not exclusively focusing on surgical technique, anesthetic protocol, or hospital/surgeon factors)?

We considered all screening questions together and made a holistic judgement about whether to screen in each paper.

Data extraction

We asked a large language model to extract each data column below from each paper. We gave the model the extraction instructions shown below for each column.

• Study Design:
• Patient Selection Criteria:
• Patient Demographic and Clinical Factors:
• Reasons for Same-Day Discharge Failure:
• Predictive Factors for Same-Day Discharge Success:
• Surgical Procedure Details:

Results

Characteristics of Included Studies

Patient Demographics

Conclusion

This report provides a comprehensive overview of the factors that predict success and failure of day-case arthroplasty, backed by statistical analysis from numerous studies. Further exploration and specific research are encouraged to clarify the inconsistency in predictions, especially concerning the younger demographic.