Table 4

Univariate predictors of use of opioid pain medication after primary total knee arthroplasty

Univariate analysis, 2-year follow-up

Univariate analysis, 5-year follow-up

Odds ratio

(95% CI)

P-value

Odds ratio

(95% CI)

P-value

Male gender (reference female)

0.51

(0.42, 0.63)

< 0.001^a

0.66

(0.52, 0.85)

0.001^a

Age (reference ≤ 60 yrs)

> 60 to 70 yrs

0.78

(0.35, 0.77)

0.001^a

0.59

(0.43, 0.80)

0.001^a

> 70 to 80 yrs

0.60

(0.47, 0.76)

< 0.001^a

0.54

(0.39, 0.73)

< 0.001^a

> 80 yrs

0.52

(0.33, 0.82)

0.04^a

0.95

(0.61, 1.49)

0.84

Body mass index (reference < 25 kg/m²)

2.0 to 29.9

1.15

(0.84, 1.59)

0.37

1.13

(0.77, 1.63)

0.54

30.0 to 34.9

1.17

(0.84, 1.62)

0.35

1.02

(0.69, 1.51)

0.92

35.0 to 39.9

1.67

(1.17, 2.38)

0.005^a

0.85

(0.54, 1.36)

0.50

≥ 40.0

2.32

(1.61, 3.35)

< 0.001^a

1.50

(0.91, 2.48)

0.11

Deyo-Charlson index (5-point change)

1.06

(0.83, 1.36)

0.62

0.88

(0.65, 1.19)

0.40

Depression (reference no depression)

1.93

(1.51, 2.47)

<0.001^a

1.85

(1.32, 2.60)

<0.001^a

Anxiety (reference no anxiety)

1.58

(1.14, 2.19)

0.006^a

1.13

(0.69, 1.85)

0.62

^aSignificant odds ratios and P-values; CI, confidence interval.

Singh and Lewallen Arthritis Research & Therapy 2012 14:R248   doi:10.1186/ar4091