| PMC full text: | Spine J. Author manuscript; available in PMC 2011 Feb 1. Published in final edited form as: Spine J. 2010 Feb; 10(2): 117. doi: 10.1016/j.spinee.2009.09.002 |
Table 2
Observed Mean outcomes (±SD) and adjusted mean differences (95% CI) between groups*
| 8 treatment sessions | 16 treatment sessions | Intervention Main Effect: SMT - LM (95% CI) | Dose Main Effect: 16 - 8 sessions (95% CI) | Interaction Effect: SMT and 16 sessions (95% CI) | ||
|---|---|---|---|---|---|---|
| CGH pain scale† | ||||||
| profile | SMT | 36.2 ± 19.8 | 28.4 ± 20.6 | -8.1 ‡ | -1.73 | -7.7 |
| LM | 42.6 ± 16.6 | 46.9 ± 18.6 | (-13.3, -2.8) | (6.9, 3.4) | (-18.0, 2.5) | |
| 12 wk | SMT | 30.8 ± 20.0 | 29.6 ± 23.7 | -10.3‡ | 1.2 | -7.8 |
| LM | 42.0 ± 20.6 | 49.4 ± 19.0 | (-18.5, -2.1) | (-6.9, 9.3) | (-24.0, 8.4) | |
| 24 wk | SMT | 33.3 ± 19.7 | 27.8 ± 26.7 | -9.8 ‡ | 0.0 | -9.2 |
| LM | 41.5 ± 18.2 | 48.6 ± 21.4 | (-18.7, -1.0) | (-8.7, 8.7) | (-26.6, 8.2) | |
| CGH disability scale† | ||||||
| profile | SMT | 27.1 ± 24.5 | 15.9 ± 20.3 | -7.9 ‡ | 0.7 | -5.3 |
| LM | 33.0 ± 22.0 | 35.0 ± 24.0 | (-13.2, -2.6) | (-4.7, 6.0) | (-15.7, 5.0) | |
| 12 wk | SMT | 20.4 ± 18.0 | 18.0 ± 27.5 | -10.0 ‡ | 2.0 | -0.6 |
| LM | 32.2 ± 23.9 | 35.4 ± 23.8 | (-18.8, -1.3) | (-6.9, 10.8) | (-17.8, 16.6) | |
| 24 wk | SMT | 22.2 ± 25.0 | 17.5 ± 22.8 | -6.1 | 2.9 | -5.8 |
| LM | 26.7 ± 17.6 | 33.3 ± 23.4 | (-15.1, 2.9) | (-6.2, 12.0) | (-23.5, 11.8) | |
| CGH number (in last 4 wk) | ||||||
| profile | SMT | 8.0 ± 6.0 | 6.9 ± 7.6 | -2.6 ‡ | 0.7 | -0.5 |
| LM | 10.5 ± 7.9 | 11.5 ± 7.4 | (-4.5, -0.7) | (-1.2, 2.6) | (-4.3, 3.3) | |
| 12 wk | SMT | 5.8 ± 4.8 | 6.4 ± 6.8 | -3.6 ‡ | 2.1 | -1.9 |
| LM | 9.8 ± 6.7 | 12.9 ± 8.8 | (-6.2, -0.9) | (-0.5, 4.7) | (-7.1, 3.3) | |
| 24 wk | SMT | 7.2 ± 5.3 | 6.6 ± 8.2 | -2.2 | 1.5 | -1.8 |
| LM | 8.7 ± 7.6 | 10.7 ± 7.5 | (-5.0, 0.6) | (-1.3, 4.3) | (-7.3, 3.8) | |
| Other headache number (in last 4 wk) | ||||||
| profile | SMT | 1.3 ± 2.2 | 1.2 ± 1.6 | -1.5 ‡ | 0.1 | -0.9 |
| LM | 2.9 ± 4.0 | 3.4 ± 4.2 | (-2.4, -0.7) | (-0.7, 0.9) | (-2.5, 0.8) | |
| 12 wk | SMT | 1.8 ± 3.3 | 1.2 ± 1.7 | -0.9 | -0.1 | -0.8 |
| LM | 2.8 ± 4.1 | 2.8 ± 2.5 | (-2.1, 0.2) | (-1.2, 1.0) | (-3.0, 1.4) | |
| 24 wk | SMT | 1.5 ± 2.4 | 1.1 ± 1.5 | -2.1 ‡ | 0.0 | -1.2 |
| LM | 3.5 ± 5.2 | 4.3 ± 5.8 | (-3.8, -0.5) | (-1.5, 1.6) | (-4.4, 1.9) | |
| Neck pain scale† | ||||||
| profile | SMT | 37.6 ± 24.4 | 30.6 ± 25.6 | -8.7 | -3.6 | -9.3 |
| LM | 44.9 ± 22.7 | 47.9 ± 22.2 | (-17.5, 0.1) | (-12.3, 5.1) | (-26.6, 7.9) | |
| 12 wk | SMT | 36.9 ± 22.9 | 32.9 ± 24.9 | -7.5 | -3.5 | -4.8 |
| LM | 47.1 ± 24.2 | 47.2 ± 21.8 | (-16.5, 1.4) | (-12.3, 5.4) | (-22.4, 12.8) | |
| 24 wk | SMT | 38.3 ± 26.3 | 28.2 ± 26.9 | -9.9 | -3.7 | -13.9 |
| LM | 42.8 ± 21.6 | 48.4 ± 23.1 | (-20.0, 0.2) | (-13.7, 6.3) | (-33.8, 6.0) | |
| Neck disability scale† | ||||||
| profile | SMT | 23.2 ± 23.8 | 15.2 ± 22.1 | -9.1 ‡ | 2.0 | -2.1 |
| LM | 32.8 ± 25.7 | 34.3 ± 24.8 | (-17.5, -0.7) | (-6.6, 10.6) | (-18.5, 14.4) | |
| 12 wk | SMT | 22.9 ± 24.8 | 14.5 ± 21.4 | -11.0 ‡ | -1.0 | 1.9 |
| LM | 37.5 ± 25.8 | 33.8 ± 21.9 | (-19.6, -2.3) | (-9.9, 7.9) | (-15.1, 18.9) | |
| 24 wk | SMT | 23.5 ± 23.6 | 15.9 ± 23.4 | -7.3 | 5.0 | -6.0 |
| LM | 28.3 ± 25.5 | 34.7 ± 27.6 | (-16.8, 2.3) | -(4.8, 14.8) | (-24.8, 12.7) | |
| Over-the-counter (times in last 4 wk) | ||||||
| profile | SMT | 8.5 ± 13.6 | 6.8 ± 8.4 | -3.2 | -1.2 | -0.6 |
| LM | 9.4 ± 11.6 | 8.2 ± 8.2 | (-6.3, 0.0) | (-4.0, 1.7) | (-6.1, 4.9) | |
| 12 wk | SMT | 6.3 ± 8.7 | 6.9 ± 8.4 | -1.8 | 0.7 | 0.3 |
| LM | 7.2 ± 9.0 | 7.3 ± 7.7 | (-5.1, 1.5) | (-2.5, 3.9) | (-6.1, 6.8) | |
| 24 wk | SMT | 8.1 ± 8.5 | 7.0 ± 8.6 | -6.0 ‡ | -0.2 | -1.0 |
| LM | 12.1 ± 12.3 | 11.7 ± 9.5 | (-10.1, -2.0) | (-4.1, 3.8) | (-8.9, 6.9) | |
SMT - spinal manipulative therapy; LM - light massage; CGH - cervicogenic headache.
*Outcomes are presented for the 12- and 24-week follow-ups, as well as for the full profile averaged across all follow-ups (4 to 24 weeks). Original data (mean ± SD) are included for the 4 study groups. The main effects are adjusted mean differences (n = 40 per comparison group). The means (with 95% confidence intervals) were adjusted in the analysis for baseline differences between groups: outcome measure, CGH pain score, number of CGH, age, gender, presence of migraine, patient’s confidence in SMT vs. LM, and expected number of SMT vs. LM treatment sessions for optimal CGH improvement. Generalized estimating equations were used to analyze the full profile and simultaneous regression was used to analyze the 12- and 24-week follow-ups; missing data were imputed. A negative main effect favors SMT over LM and favors 16 treatment sessions over 8 treatment sessions. A negative interaction effect shows that a treatment effect favoring SMT is greater for 16 sessions than for 8 sessions, and that a dose effect favoring 16 sessions is greater for SMT than for LM. See Table 3.
†Modified Von Korff scale (scored from 0 to 100 points with lower score preferable). The pain scale is the primary outcome.
‡P < .05.