Psychological distress before total knee arthroplasty is associated with longer hospital stay after surgery

Abstract

Purpose: To investigate the association between pre-operative psychological health and hospital length of stay following total knee arthroplasty. Methods: A prospective observational study of 91 participants was conducted at two hospitals in Western Sydney Local Health District, Australia. Participants were scheduled for a unilateral, primary total knee arthroplasty (TKA) and lived within our Local Health District. We excluded those with moderate or severe cognitive impairment or planned orthopaedic surgery within six months of the index TKA. Pre-operative measures included sociodemographic data, anthropometric data, pain, function, leg strength, fatigue, resilience and quality of life. Psychological distress was measured using the Depression, Anxiety and Stress Scale-21 (DASS-21). Participants who reported any level of psychological distress on the DASS-21 before TKA were assigned to the “psychologically distressed” group. All other participants were assigned to the “psychologically well” group. Our primary outcomes were acute hospital length of stay (LOS, in calendar days) and incidence of inpatient complications. Non-parametric methods were used to compare groups on primary outcomes. Generalized linear modelling with Poisson loglinear distribution was used to conduct univariate and multivariate analysis in order to determine pre-operative factors affecting length of stay. Results: Data is presented for 75 participants (16 excluded due to incomplete baseline data, no loss to follow-up) (Figure). The psychologically distressed group had a significantly longer hospital length of stay compared to the psychologically well group (median LOS 5.0 days (IQR 2) vs 6.0 days (IQR 3), Mann Whitney U = 495.500, p = 0.028), with no significant difference in inpatient complications between groups (p > 0.05). Leg strength was the only significant predictor of LOS on multivariate generalized linear modelling (OR -0.972, 95%CI OR 0.946-1.000, p = 0.047). Conclusions: Psychological distress before TKA is associated with longer LOS after surgery. Assessing psychological health needs to be standard care for elective arthroplasty and can be feasibly performed by clinicians already embedded in orthopaedic care. Further research to improve perioperative pathways needs to consider optimizing both psychological and physical health.