Abstract
The relationship between pain catastrophising and emotional disorders including anxiety and depression in patients with osteoarthritis (OA) undergoing total joint replacement (TJR) is an emerging area of study. The purpose of this study was to examine the association between pain catastrophising, anxiety, depression and preoperative patient characteristics.
A prospective cohort study of preoperative TJR patients at one centre over 12-months was conducted. We examined association between catastrophising, anxiety, depression and preoperative patient characteristics including demographics, pain and function. Pain catastrophising was assessed using the Pain Catastrophising Scale (PCS), and anxiety/depression using the Hospital Anxiety and Depression Scale (HADS-A, HADS-D). Patient perceived level of hip/knee pain was measured using a visual analogue (VAS) pain scale. Patient perception of function was measured using the Oxford Score. Preoperative radiographic grading of OA was determined using the Kellgren and Lawrence (K-L) scale. Logistic regression was used to assess pattern of relationship between preoperative characteristics and PCS or HADS. Adjusted odds ratio (OR) and 95% confidence interval (CI) were reported. A secondary quantile regression analysis examined whether a model not restricted to pre-defined PCS and HADS categories would yield comparable results to the logistic regression model described in the primary analysis. P-values less than 0.05 were considered statistically significant.
The sample included 463 TJR patients (178 hips, 285 knees). VAS pain (OR 1.23,95%CI 1.04–1.45) and Oxford score (OR 1.13,95%CI 1.07–1.20) were identified as significant predictors for PCS. The same two variables were the strong predictors for all sub-domains of PCS excluding rumination. Oxford Score was the only significant predictor for abnormal HADS-A (OR 1.10,95%CI 1.04–1.17) while VAS pain (OR 1.27,95%CI 1.02–1.52) and Oxford (OR 1.09,95%CI 1.01–1.17) were significant predictors for abnormal HADS-D. Similar pattern of association for PCS and HADS was observed in the quantile regression model, where larger VAS pain and Oxford scores significantly increased median PCS across all domains. Female gender, younger age or having a higher ASA grade were associated with higher median HADS-A, but unlike in the logistic regression, this association was statistically significant.
Pain catastrophising and emotional disorders generally result in poor functional outcomes in TJR patients. The most important predictor of catastrophising, anxiety/depression is pain and subjective function. At risk patients include those with high preoperative pain with generally good preoperative function, as well as younger females with significant comorbidities. Such patients should be identified, and targeted psychological therapy implemented preoperatively to optimise coping strategies and adaptive behaviour to mitigate inferior TJR outcomes including pain and patient dissatisfaction.
