Table 5.

Studies evaluating postoperative psychological factors as risk factors for chronic pain after TKR

Author and year	Number in analysis	Risk factor measurement	Outcome(s)	Univariable or multivariable analysis	Association	Results summary
Stephens et al, 200248	63	Perceived positive social support (MOS social support survey) at 6 weeks	WOMAC pain at 6 months	Multivariable hierarchical multiple regression	Yes	Beta=−0.29, SE=0.09, p≤0.05
		Perceived negative social support (four items) at 6 weeks			Yes	Beta=−0.27, SE=0.14, p≤0.05
		Active coping (Vanderbilt Multidimensional Pain Coping Inventory Active Coping scale) at 6 weeks			No	Beta=−0.14, SE=0.01
		Avoidant coping (Vanderbilt Multidimensional Pain Coping Inventory Avoidant Coping scale) at 6 weeks			No	Beta=0.21, SE=0.01
Edwards et al, 200939	43	Catastrophising (Coping Strategies Questionnaire catastrophising subscale) at 1 month and 3 months	Global pain VAS at 6 and 12 months Night pain VAS at 6 and 12 months	Multivariable generalised estimating equation model	No Yes	Catastrophising at a previous time point was not a predictor of global pain at a future time point (estimate=2.1, SE=2.2, t=0.9, p=0.35). Catastrophising at a previous time was a predictor of night-time pain at a future time point (estimate=5.1, SE=2.5, t=2.0, p=0.04).
		Depression (Center for Epidemiological Studies Depression Scale at 1 month and 3 months)	Global pain VAS at 6 and 12 months Night pain VAS at 6 and 12 months		Yes No	Depression at a previous time point was a predictor of global pain at a future time point (estimate=0.67, SE=0.30, t=2.2, p=0.03). Depression at a previous time point was not a predictor of night-time pain at a future time point (estimate=0.40, SE=0.33, t=1.2, p=0.24).
Pinto et al, 201345	42	Anxiety scale (Hospital Anxiety and Depression Scale) at 48 hours	NRS at 4–6 months	Hierarchical logistic regression	Yes	Exp(B)=1.713 (95% CI 1.104 to 2.657), p=0.016
Kocic et al, 201550	78	Fear of movement (Tampa Scale of Kinesiophobia) at 2 weeks	NRS at 6 months	Univariable comparison of means	Yes	Patients with high fear of movement had more pain (mean=3.24, SD=1.98) than patients with low fear of movement (mean=1.81, SD=1.5), p=0.0035.

NRS, Numerical Rating Scale; TKR, total knee replacement; VAS, Visual Analogue Scale; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index.