This study aimed to identify the preoperative patient-related characteristics predicting inpatient recovery of functioning and/or length of hospital stay following elective primary total hip arthroplasty. A search was conducted of the electronic databases MEDLINE, EMBASE and CINAHL from inception through April 2014. Observational studies were selected for systematic review if they identified clinically relevant preoperative prognostic factors and reported a connection between inpatient recovery of physical functioning and/or length of hospital stay. Study participants were adults undergoing an elective primary total hip arthroplasty. Fourteen studies were included, a total of 199,410 individual total hip arthroplasty procedures. Two studies investigated inpatient recovery of physical functioning, no strong level of evidence was found for a relationship between functional recovery and any of the preoperative predictors. Twelve studies investigated the length of hospital stay and reported 19 preoperative prognostic factors. A strong level of evidence suggested that higher scores on the American Society of Anaesthesiologists assessment (OR 3.34 to 6.22, +0.20 days), increased number of comorbidities (RR of 1.10, +0.59 to 1.61 days), presence of heart disease, (RR of 1.59, +0.26 days), and presence of lung disease (RR of 1.30, +0.34 days) were related to longer lengths of hospital stay following total hip arthroplasty.
For the prediction of inpatient recovery of physical functioning there weren’t any factors with a strong level of evidence found. For length of stay there was a strong level of evidence for the American Society of Anaesthesiologists score, number of comorbidities, and presence of heart or lung disease.