Table 2. Primary and Secondary Outcomesa.
Characteristic | Experimental Treatment | Control Treatment | Group Difference, Mean (95% CI) | Effect Size | Main Effect of Time | Interaction Effect | Bonferroni Post Hoc Tests | |||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Estimated Marginal Mean (SE) | Change Relative to Baseline, % | Estimated Marginal Mean (SE) | Change Relative to Baseline, % | F Score | P Value | F Score | P Value | Time | Group | |||
Pain as a Primary Outcome Measure | ||||||||||||
PPT prim, kgfb | ||||||||||||
Baseline | 4.558 (0.339) | NA | 4.429 (0.330) | NA | 0.129 (−1.064 to 0.806) | NA | 37.483 | .23 | 4.866 | .03 |
P < .001c; P = .009d |
P = .06c,d |
At 3 mo | 6.148 (0.353) | 25.86 | 5.177 (0.363) | 14.45 | 0.971 (−0.028 to 1.970) | .46 | ||||||
PPT hand, kgf | ||||||||||||
Baseline | 3.598 (0.250) | NA | 3.604 (0.243) | NA | −0.006 (−0.695 to 0.683) | NA | 20.977 | <.001 | 1.738 | .19 | P < .001c,d | NA |
At 3 mo | 4.413 (0.260) | 18.47 | 4.049 (0.267) | 11.00 | 0.364 (−0.372 to 1.100) | .26 | ||||||
PPT leg, kgf | ||||||||||||
Baseline | 5.328 (0.357) | NA | 5.077 (0.348) | NA | 0.250 (−0.736 to 1.237) | NA | 21.168 | <.001 | 2.583 | .11 | P < .001c,d | NA |
At 3 mo | 6.544 (0.372) | 18.59 | 5.654 (0.382) | 10.21 | 0.889 (−0.164 to 1.942) | .31 | ||||||
CPM primb | ||||||||||||
Baseline | 1.075 (0.196) | NA | 1.054 (0.193) | NA | 0.021 (−0.522 to 0.564) | NA | 3.259 | .07 | 2.480 | .12 | NA | NA |
At 3 mo | 1.511 (0.211) | 28.86 | 1.190 (0.224) | 11.43 | 0.321 (−0.287 to 0.928) | .16 | ||||||
CPM leg | ||||||||||||
Baseline | 1.058 (0.205) | NA | 0.904 (0.199) | NA | 0.154 (−0.719 to 0.411) | NA | 1.505 | .22 | 0.019 | .89 | NA | NA |
At 3 mo | 1.259 (0.221) | 15.97 | 1.156 (0.234) | 21.80 | 0.103 (−0.532 to 0.739) | .09 | ||||||
NRS score (of 10) | ||||||||||||
Baseline | 5.153 (0.247) | NA | 4.983 (0.245) | NA | 0.169 (−0.519 to 0.858) | NA | 34.831 | <.001 | 2.172 | .10 | Baseline >3, 6, 12 mo (P < .001c,d) |
NA |
At 3 mo | 2.462 (0.302) | −52.22 | 3.332 (0.311) | −33.13 | −0.871 (−1.731 to −0.010) | .52 | ||||||
At 6 mo | 2.948 (0.326) | −42.79 | 3.808 (0.341) | −23.58 | −0.859 (−1.796 to 0.078) | .43 | ||||||
At 12 mo | 2.655 (0.308) | −48.48 | 3.369 (0.315) | −32.39 | −0.714 (−1.588 to 0.160) | .44 | ||||||
CSI score (of 100) | ||||||||||||
Baseline | 40.017 (1.473) | NA | 39.883 (1.473) | NA | 0.133 (−3.992 to 4.259) | NA | 39.254 | <.001 | 7.537 | .003 | Baseline >3, 6, 12 mo (P < .001c; P ≤ .003d) |
6 mo (P = .02); 12 mo (P = .01) |
At 3 mo | 30.668 (1.690) | −23.36 | 35.235 (1.714) | −11.65 | −4.567 (−9.334 to 0.201) | .68 | ||||||
At 6 mo | 28.538 (1.732) | −28.69 | 34.222 (1.769) | −14.19 | −5.684 (−10.589 to −0.780) | .73 | ||||||
At 12 mo | 29.358 (1.671) | −26.64 | 35.410 (1.703) | −11.22 | −6.053 (−10.781 to −1.324) | .74 | ||||||
Function as a Primary Outcome Measure | ||||||||||||
PDI score (of 70) | ||||||||||||
Baseline | 21.800 (1.811) | NA | 21.583 (1.811) | NA | 0.217 (−4.856 to 5.289) | 34.979 | <.001 | 2.999 | .03 | Baseline >3, 6, 12 mo (P < .001c,d) |
3 mo (P = .04); 6 mo (P = .01); 12 mo (P = .01) |
|
At 3 mo | 9.384 (1.720) | −56.95 | 14.497 (1.762) | −32.83 | −5.113 (−9.994 to −0.232) | .49 | ||||||
At 6 mo | 7.884 (1.688) | −63.83 | 14.235 (1.720) | −34.05 | −6.351 (−11.153 to −1.550) | .56 | ||||||
At 12 mo | 8.138 (1.605) | −62.67 | 13.916 (1.649) | −35.52 | −5.779 (−10.340 to −1.217) | .48 | ||||||
SF36 mental health component score (of 400) | ||||||||||||
Baseline | 279.344 (9.121) | NA | 280.242 (9.121) | NA | −0.897 (−26.440 to 24.646) | NA | 7.019 | <.001 | 3.213 | .03 | Baseline <3, 6, 12 mo (P < .001c) |
6 mo (P = .01) |
At 3 mo | 316.700 (9.427) | 11.80 | 293.030 (9.717) | 4.36 | 23.670 (−3.168 to 50.509) | .42 | ||||||
At 6 mo | 320.942 (10.002) | 12.96 | 284.446 (10.326 | 1.24 | 36.496 (7.998 to 64.995) | .62 | ||||||
At 12 mo | 316.204 (12.192) | 11.66 | 291.520 (12.582) | 3.87 | 24.685 (−10.092 to 59.461) | .27 | ||||||
SF36 physical health component score (of 400) | ||||||||||||
Baseline | 235.750 (9.540) | NA | 225.625 (9.540) | NA | 10.125 (−16.593 to 36.843) | NA | 45.269 | <.001 | 4.983 | .003 | Baseline <3, 6, 12 mo (P < .001c,d) |
3 mo (P = .009); 6 mo (P < .001); 12 mo (P = .03) |
At 3 mo | 304.915 (10.036) | 22.68 | 266.652 (10.366) | 15.39 | 39.263 (9.644 to 66.882) | .46 | ||||||
At 6 mo | 320.130 (10.277) | 26.36 | 267.123 (10.552) | 15.54 | 53.007 (23.805 to 82.209) | .78 | ||||||
At 12 mo | 314.764 (10.475) | 25.30 | 282.557 (10.769) | 20.15 | 32.208 (2.402 to 62.014) | .30 | ||||||
Secondary Outcome Measures | ||||||||||||
TSK score (of 68) | ||||||||||||
Baseline | 34.367 (0.900) | NA | 36.717 (0.900) | NA | −2.350 (−4.870 to 0.170) | NA | 53.394 | <.001 | 13.165 | <.001 | Baseline >3, 6, 12 mo (P < .001c; P ≤ .007d) |
3 mo (P < .001); 6 mo (P < .001); 12 mo (P < .001) |
At 3 mo | 24.349 (0.838) | −29.15 | 33.029 (0.714) | −10.04 | −8.680 (−11.067 to −6.294) | 1.11 | ||||||
At 6 mo | 23.904 (0.871) | −30.44 | 33.714 (0.904) | −8.18 | −9.810 (−12.301 to −7.320) | 1.25 | ||||||
At 12 mo | 24.020 (0.785) | −30.11 | 32.882 (0.808) | −10.44 | −8.862 (−11.097 to −6.628) | 1.14 | ||||||
PVAQ score (of 80) | ||||||||||||
Baseline | 36.900 (1.587) | NA | 35.767 (1.587) | NA | 1.133 (−3.312 to 5.579) | NA | 20.764 | <.001 | 6.374 | .001 | Baseline >3, 6, 12 mo (P < .001c) |
3 mo (P = .001); 6 mo (P = .005); 12 mo (P = .01) |
At 3 mo | 24.878 (1.648) | −32.58 | 33.142 (1.699) | −7.34 | −8.265 (−12.959 to −3.571) | .88 | ||||||
At 6 mo | 24.740 (1.762) | −32.95 | 32.008 (1.823) | −10.51 | −7.269 (−12.294 to −2.243) | .79 | ||||||
At 12 mo | 25.346 (1.673) | −31.31 | 31.662 (1.673) | −11.48 | −6.316 (−11.070 to −1.561) | .73 | ||||||
PCS total score (of 52) | ||||||||||||
Baseline | 16.533 (1.310) | NA | 16.850 (1.310) | NA | −0.317 (−3.986 to 3.353) | NA | 41.653 | <.001 | 1.609 | .19 | Baseline >3, 6, 12 mo (P < .001c,d); 3 mo >6, 12 mo (P = .001c,d) |
NA |
At 3 mo | 8.845 (1.201) | −46.50 | 12.496 (1.233) | −25.84 | −3.652 (−7.065 to −0.239) | .44 | ||||||
At 6 mo | 6.576 (1.145) | −60.23 | 9.550 (1.183) | −43.32 | −2.974 (−6.239 to 0.291) | .36 | ||||||
At 12 mo | 6.051 (1.135) | −63.40 | 9.488 (1.171) | −43.69 | −3.437 (−6.673 to −0.201) | .35 |
Abbreviations: CPM, conditioned pain modulation; CSI, Central Sensitization Inventory; kgf, kilogram force; NA, not applicable; NRS, Numeric Rating Scale; PCS, Pain Catastrophizing Scale, PDI, Pain Disability Index; PPT, pressure pain threshold; prim, primary (pain) test site; PVAQ, Pain Vigilance and Awareness Questionnaire; SF36, 36-Item Short Form Health Survey; TSK, Tampa Scale for Kinesiophobia.
All analyses were performed using linear mixed models. The Cohen d is interpreted as very large (>1.3), large (0.80-1.29), medium (0.50-0.79), small (0.20-0.49), and negligible (<0.20).
Values of people with neck pain and low back pain measures at the primary test site were analyzed together, using PPT location as confounding factor within the linear mixed models analysis.
Results of Bonferroni post hoc tests in the experimental group.
Results of Bonferroni post hoc tests in the control group.