Table 2. Pain Intensity Score (Primary Outcome)a,b Among Participants With Chronic Low Back Pain.
| Overall Effect | Intervention Group, Mean (95% CI) | Control Group, Mean (95% CI) | Between-Group Difference, Mean (95% CI)c | P Value |
|---|---|---|---|---|
| Facet joint trial, No. of participants | 125 | 126 | ||
| Overall | −0.08 (−0.50 to 0.34) | .71 | ||
| 3 wk | 5.17 (4.73 to 5.61) | 5.92 (5.58 to 6.26) | −0.41 (−1.02 to 0.19) | .18 |
| 6 wk | 5.19 (4.76 to 5.61) | 5.90 (5.53 to 6.26) | −0.38 (−0.96 to 0.20) | .20 |
| 3 mo | 5.01 (4.59 to 5.43) | 5.44 (5.03 to 5.85) | −0.18 (−0.76 to 0.40) | .55 |
| 6 mo | 4.61 (4.18 to 5.04) | 4.84 (4.38 to 5.30) | −0.04 (−0.63 to 0.56) | .91 |
| 9 mo | 4.66 (4.20 to 5.00) | 4.73 (4.24 to 5.22) | 0.19 (−0.41 to 0.80) | .53 |
| 12 mo | 4.49 (4.00 to 4.97) | 4.44 (3.94 to 4.94) | 0.47 (−0.14 to 1.07) | .13 |
| Sacroiliac joint trial, No. of participants | 116 | 112 | ||
| Overall | −0.40 (−0.83 to 0.03) | .07 | ||
| 3 wk | 4.96 (4.51 to 5.40) | 6.00 (5.59 to 6.41) | −0.96 (−1.63 to −0.29) | .005 |
| 6 wk | 5.22 (4.81 to 5.64) | 5.69 (5.31 to 6.08) | −0.53 (−1.17 to 0.10) | .10 |
| 3 mo | 4.77 (4.31 to 5.24) | 5.45 (4.94 to 5.95) | −0.71 (−1.35 to −0.06) | .03 |
| 6 mo | 4.50 (4.01 to 4.98) | 4.78 (4.24 to 5.31) | −0.12 (−0.77 to 0.53) | .73 |
| 9 mo | 5.03 (4.55 to 5.51) | 4.97 (4.39 to 5.56) | 0.16 (−0.51 to 0.83) | .64 |
| 12 mo | 4.65 (4.16 to 5.13) | 4.84 (4.30 to 5.38) | −0.07 (−0.74 to 0.60) | .83 |
| Combination trial, No. of participants | 103 | 99 | ||
| Overall | −0.21 (−0.76 to 0.35) | .47 | ||
| 3 wk | 5.45 (4.95 to 5.95) | 6.40 (5.91 to 6.89) | −0.65 (−1.47 to 0.17) | .12 |
| 6 wk | 5.37 (4.89 to 5.85) | 6.09 (5.65 to 6.52) | −0.40 (−1.14 to 0.34) | .29 |
| 3 mo | 4.77 (4.25 to 5.30) | 5.94 (5.42 to 6.45) | −0.99 (−1.73 to −0.25) | .01 |
| 6 mo | 4.92 (4.39 to 5.44) | 4.95 (4.35 to 5.54) | 0.33 (−0.53 to 1.09) | .39 |
| 9 mo | 5.01 (4.47 to 5.56) | 5.25 (4.65 to 5.86) | −0.05 (−0.82 to 0.73) | .90 |
| 12 mo | 4.85 (4.24 to 5.46) | 4.38 (3.73 to 5.03) | 0.69 (−0.10 to 1.49) | .09 |
Abbreviation: NNT, number needed to treat.
a
Measured by numeric rating scale (score range, 0-10); a higher score indicates more severe symptoms.
b
The overall effect measures provide information over the total follow-up time of 12 mo, instead of the time × treatment effects.
c
Values presented (for mean differences) are model estimates of linear mixed-effects models with a random intercept, and adjusted for outcome at baseline and age, sex, body mass index, education, smoking, marital status, back pain complaint history, and participant expectations. Regression coefficients can be interpreted as mean differences between interventions at a certain follow-up point compared with baseline.