Table 4

Linear regression preformed to determind predictors of poor changes preoperatively to the 2 years follow-up of the KOOS subscales pain.

Univeriate analysis
 Multivariate analysisII
Predictor Variable
 Na
 Cb
 (95% CI)
 pc
 R2 adjd
 Cb
 (95% CI)
 pc
Age (year)
 52
 0.27
 (-0.62–1.17)
 0.54
 0%
Not included
BMI (kg/m2)
 48
 0.62
 (-0.89–2.12)
 0.41
 0%
Not included
Preop pain (0–100)
 52
 '-0.61
 (-0.92–-0.29)
 0.0003
 21%
 '-0.6
 (-0.9–-0.2,8)
 0.0004
Sex
 52
 1.42
 (-10.77–13.6)
 0.82
 0%
Not included
0: female
 26






1: male
 26






Acceptable 2 year HKA-angle
 42
 8.78
 (-12.81–30.38)
 0.41
 0%
Not included
0: no
 7






1: yes
 37






Smoker
 52
 '-0.35
 (-15.27–14.56)
 0.96
 0%
Not included
0: no
 40






1: yes
 12






Complication
 51
 '-15.8
 (-16.6–7.94)
 0.06
 0.5%
 '-14.7
 (-29.4–0.08)
 0.05
0: no
 43






1: yes
 8






aNumber of patients included

bEstimated change of changes in preoperative until 2 years postoperative pain per unit change predictor variable; 95% confidence interval (CI) within paranthesis.

cP value for effect of predictor variable.

cFraction of changes of preopertive until 2 years postoperative pain variance explaind by each predictor (adjusted value).

W-Dahl et al. BMC Musculoskeletal Disorders 2005 6:18   doi:10.1186/1471-2474-6-18