Table 2.
Regression Coefficients of Factors Associated With Pain Reduction at 3 and 12 Months After Interventiona
| Knee OA b | Hip OA b | |||
|---|---|---|---|---|
| Baseline Characteristics | 3 Months B (95% CI) | 12 Months B (95% CI) | 3 Months B (95% CI) | 12 Months B (95% CI) |
| Baseline pain (0–10) | −0.67 (−0.69 to − 0.65) | −0.70 (−0.72 to − 0.67) | −0.64 (−0.67 to 0.66) | −0.66 (−0.70 to − 0.63) |
| Age (y) | 0.00 (0.00 to 0.01) | 0.01 (0.01 to 0.02) | n/a | n/a |
| BMI | 0.02 (0.02 to 0.03) | 0.03 (0.02 to 0.04) | 0.02 (0.01 to 0.03) | 0.04 (0.03 to 0.06) |
| Sex | ||||
| Men | Reference | Reference | Reference | Reference |
| Women | n/a | n/a | 0.078 (−0.23 to 0.18) | n/a |
| Quality of life (0–100) | −0.01 (−0.01 to − 0.01) | −0.01 (−0.01 to − 0.01) | −0.01 (−0.01 to − 0.00) | −0.01 (−0.01 to − 0.00) |
| Physical activity (min/wk) | ||||
| <150 | Reference | Reference | Reference | Reference |
| ≥150 | n/a | n/a | n/a | −0.15 (−0.26 to − 0.04) |
| Living situation | ||||
| Live with someone | Reference | Reference | Reference | Reference |
| Live alone | n/a | n/a | n/a | 0.12 (−0.00 to 0.24) |
| Education (y) | ||||
| Low (0–14) | Reference | Reference | Reference | Reference |
| High (>14) | −0.12 (−0.19 to − 0.05) | −0.24 (−0.32 to − 0.16) | −0.13 (−0.23 to − 0.02) | −0.16 (−0.28 to −0.38) |
| Pain frequency | ||||
| Every week or less often | Reference | Reference | Reference | Reference |
| Every day or all the time | 0.36 (0.27 to 0.45) | 0.35 (0.26 to 0.44) | 0.28 (0.14 to 0.41) | 0.34 (0.19 to 0.50) |
| Charnley class | ||||
| A (1 joint with OA) | Reference | Reference | Reference | Reference |
| B (bilateral OA) | 0.38 (0.30 to 0.46) | 0.50 (0.34 to 0.67) | 0.13 (−0.03 to 0.29) | 0.10 (−0.84 to 0.28) |
| C (bilateral OA + other comorbidities) | 0.49 (0.41 to 0.56) | 0.71 (0.56 to 0.86) | 0.22 (0.11 to 0.33) | 0.32 (0.20 to 0.44) |
| Walking difficulties due to OA | ||||
| No | Reference | Reference | Reference | Reference |
| Yes | n/a | 0.20 (0.11 to 0.29) | 0.16 (0.03 to 0.29) | 0.38 (0.24 to 0.52) |
| Drugs for OA in last 3 mo | ||||
| No | Reference | Reference | Reference | Reference |
| Yes | n/a | n/a | n/a | 0.16 (0.04 to 0.28) |
| Previous surgery | ||||
| No | Reference | Reference | Reference | Reference |
| Yes | 0.12 (0.03 to 0.20) | 0.33 (0.23 to 0.42) | n/a | n/a |
| Previous surgery contralateral | ||||
| No | Reference | Reference | Reference | Reference |
| Yes | 0.07 (−0.29 to 0.18) | 0.07 (−0.02 to 0.19) | n/a | n/a |
| Previous physical therapy | ||||
| No | Reference | Reference | Reference | Reference |
| Yes | 0.15 (0.08 to 0.21) | 0.16 (0.09 to 0.23) | 0.09 (−0.011 to 0.186) | 0.16 (0.05 to 0.27) |
| Willingness to undergo surgery | ||||
| No | Reference | Reference | Reference | Reference |
| Yes | 0.36 (0.28 to 0.45) | 0.51 (0.42 to 0.61) | 0.50 (0.363 to 0.632) | 0.50 (0.35 to 0.65) |
| Fear of movement | ||||
| No | Reference | Reference | Reference | Reference |
| Yes | −0.10 (−0.01 to − 0.03) | −0.23 (−0.33 to − 0.13) | n/a | −0.15 (−0.31 to 0.01) |
| ASES pain (0–100) | −0.01 (−0.01 to − 0.01) | −0.01 (−0.01 to − 0.01) | −0.01 (−0.013 to − 0.007) | −0.01 (−0.01 to − 0.01) |
| ASES symptoms (0–100) | −0.00 (−0.01 to 0.00) | −0.00 (−0.01 to 0.00) | n/a | n/a |
a ASES = Arthritis Self-Efficacy Scale; B = unstandardized regression coefficient; BMI = body mass index; n/a = not available due to being dropped during the backward elimination process; OA = osteoarthritis.
b
Statistically significant results are reported in bold.