Skip to main content

Table 3 Participants obtaining 30% and 50% improvement in outcomes: odds ratio*

From: Illustrating risk difference and number needed to treat from a randomized controlled trial of spinal manipulation for cervicogenic headache

Improvement criterion SMT (n = 36) LM (n = 39) adjusted odds ratio
(95% CI)
P
Cervicogenic headache pain scale †
30% 12 wk 47% 38% 2.2 (0.8, 6.0) .142
  24 wk 58% 49% 2.3 (0.8, 6.5) .122
50% 12 wk 42% 23% 3.0 (1.1, 8.3) .033
  24 wk 42% 23% 3.6 (1.3, 9.7) .011
Cervicogenic headache number (in last 4 wk)
30% 12 wk 72% 51% 4.4 (1.3, 14.3) .015
  24 wk 78% 62% 3.1 (0.9, 11.2) .082
50% 12 wk 64% 46% 2.6 (0.9, 7.5) .067
  24 wk 61% 51% 1.9 (0.7, 5.2) .225
Cervicogenic headache disability scale †
30% 12 wk 64% 51% 2.0 (0.7, 5.7) .193
  24 wk 61% 64% 0.9 (0.3, 2.4) .803
50% 12 wk 64% 36% 3.8 (1.3, 11.0) .014
  24 wk 56% 38% 2.2 (0.9, 5.9) .102
  1. SMT - spinal manipulative therapy; LM - light massage; NNT - number needed to treat
  2. * Outcomes are presented for the 12-week (short-term) and 24-week (intermediate-term) follow-ups. The SMT and LM group percentages are unadjusted. Missing data were imputed except for five participants with no follow-up data. Odds ratios were adjusted for differences between groups in the baseline value of the outcome and all randomization variables. Ratios greater than 1.0 favor spinal manipulation.
  3. † Modified Von Korff scale (scored from 0 to 100 points before dichotomization).