Determinants of pain, functional limitations and health-related quality of life six months after total knee arthroplasty: results from a prospective cohort study

Table 4 Association between the study participants’ characteristics and the SF-36 health-related quality of life scores 6 months after total knee arthroplasty (n = 138)

SF-36 SCORE 6 MONTHS AFTER TKA ^†	β^‡	95% CI	p value
Physical functioning (R ² = 0.23)
SF-36 Physical functioning score before surgery (%)	0.24	0.01 to 0.47	0.036
Presence of contralateral knee pain before surgery^§	- 12.68	- 20.37 to - 4.99	0.001
Psychological distress (PSI score /42)	- 0.54	- 1.06 to - 0.02	0.04
Comorbidities (CIRS score / 56)	- 2.60	−4.11 to - 1.08	<0.001
Role-physical (R ² = 0.17)
SF-36 Role-physical score before surgery (%)	0.31	0.12 to 0.51	0.01
Comorbidities (CIRS score /56)	- 2.02	- 3.91 to - 0.13	0.04
Number of in-hospital complications^¶	−7.41	- 14.23 to - 0.69	0.03
Bodily Pain (R ² = 0.13)
SF-36 Bodily pain score before surgery (%)	0.72	0.43 to 1.01	<0.001
Presence of contralateral knee pain before surgery	−7.45	−14.34 to - 0.55	0.03
Comorbidities (CIRS score /56)	- 1.97	- 3.37 to - 0.57	0.001
Number of in-hospital complications^¶	−5.47	- 10.52 to - 0.39	0.04

TKA: Total knee arthroplasty.
^† Stepwise multiple regression analysis.
^‡ Multivariate unstandardized linear regression coefficients. For each unit of the participants’ characteristics there is on average a β increase (+) or a decrease (−) on the SF-36 score. A positive β has a positive effect on the participants’ condition and a negative β has a negative effect.
SF-36 scores before surgery, psychological distress and comorbidities treated as continuous variables. Higher scores signify better patient status.
Other independent variables are categorical.
^§ Presence compared to absence of contralateral knee pain as measured by the WOMAC pain scale.
^¶ Reference category = 0 compared to 1 or ≥ 2 complications.

ISSN: 2052-1847