Table 4

Mean scores, mean change within group and mean difference between groups for VAS at baseline/1st session, 2nd session, 3rd session, 4th session, week 4, week 8, week 12, week 26 and week 52

VariableAdjusted mean difference between groups
(95% CI)
P value*
(effect size)†
DN mean (SD)DN mean change from baseline
(95% CI)
PNE mean (SD)PNE mean change from baseline (95% CI)
VAS average
 Baseline/1st session6.0 (2.3)5.9 (2.4)
 2nd session4.6 (2.2)‡−1.4 (−2.5 to −0.3)4.4 (2.7)‡−1.5 (−2.5 to −0.5)0.14 (−0.64 to 0.92)0.725 (0.001)
 3rd session4.0 (2.4)‡−2.0 (−3.3 to −0.7)4.1 (2.8)‡−1.8 (−3.1 to −0.5)0.16 (−1.11 to 0.79)0.743 (0.001)
 4th session3.5 (2.5)‡−2.6 (−3.9 to −1.2)3.4 (2.7)‡−2.5 (−3.8 to −1.1)0.01 (−0.95 to 0.97)0.984 (0.001)
 Week 42.6 (2.5)‡−3.5 (−4.9 to −2.0)3.8 (3.0)‡−2.0 (−3.2 to −0.8)−1.36 (−2.37 to 0.35)0.009 (0.067)§
 Week 83.3 (2.8)‡−2.7 (−4.2 to −1.2)3.8 (2.7)‡−2.1 (−3.4 to −0.8)−0.54 (−1.57 to 0.49)0.298 (0.011)
 Week 123.3 (2.7)‡−2.7 (−4.2 to −1.2)3.7 (2.8)‡−2.1 (−3.6 to −0.7)−0.46 (−1.51 to 0.58)0.381 (0.008
 Week 263.4 (2.8)‡−2.6 (−4.0 to −1.2)3.4 (2.7)‡−2.5 (−3.8 to −1.1)−0.06 (−0.97 to 1.09)0.911 (0.001)
 Week 523.4 (2.8)‡−2.6 (−4.0 to −1.2)2.8 (3.0)‡−3.0 (−4.5 to −1.6)0.508 (−0.57 to 1.58)0.351 (0.009)
 Main effect of time; p value<0.001<0.001
VAS maximum
 Baseline/1st session7.6 (2.0)7.5 (2.3)
 2nd session6.2 (2.3)‡−1.3 (−2.3 to −0.3)5.5 (2.9)‡−2.0 (−3.0 to −0.9)0.66 (−0.18 to 1.50)0.122 (0.024)
 3rd session5.4 (2.6)‡−2.2 (−3.6 to −0.8)5.3 (3.1)‡−2.2 (−3.6 to −0.8)0.05 (−1.03 to 1.13)0.926 (0.001)
 4th session4.9 (2.9)‡−2.7 (−4.1 to −1.3)4.5 (3.0)‡−3.0 (−4.4 to −1.6)0.31 (−0.76 to 1.39)0.563 (0.003)
 Week 43.6 (3.2)‡−3.9 (−5.5 to −2.3)4.9 (3.5)‡−2.6 (−4.1 to −1.1)−1.28 (−2.53 to −0.04)0.043 (0.041)§
 Week 84.7 (3.4)‡−2.8 (−4.5 to −1.2)5.0 (3.1)‡−2.5 (−3.8 to −1.2)−0.32 (−1.50 to 0.87)0.599 (0.003)
 Week 124.7 (3.3)‡−2.9 (−4.5 to −1.3)5.1 (3.1)‡−2.4 (−3.9 to −1.0)−0.42 (−1.63 to 0.78)0.487 (0.005)
 Week 264.5 (3.2)‡−3.0 (−4.6 to −1.4)4.6 (3.1)‡−2.9 (−4.5 to −1.2)−0.13 (−1.34 to 1.09)0.838 (0.001)
 Week 524.5 (3.2)‡−3.0 (−4.6 to −1.4)4.1 (3.4)‡−3.4 (−5.1 to −1.8)0.45 (−0.80 to 1.70)0.480 (0.005)
 Main effect of time; p value<0.001<0.001
  • Positive between group differences represent greater change (improvement) in the PNE group compared with the DN group.

  • *P value after Bonferroni’s correction between group.

  • †Eta-squared (η²); between groups effect size.

  • ‡P<0.05 after Bonferroni’s correction comparing follow-up against baseline scores within group.

  • §P<0.05, significant differences between groups.

  • DN, dry needling; PNE, percutaneous needle electrolysis; VAS, visual analogue scale (0 corresponds to absence of pain; 10, maximum tolerable pain).;