Table 4.
Secondary Outcomes
| Observed unadjusted Mean (SD) |
Slope (95%CI) | Adjusted Mean difference (95% CI) |
||||||
|---|---|---|---|---|---|---|---|---|
| SMT 0 | SMT 6 | SMT 12 | SMT 18 | per 6 SMT sessions | SMT 0 vs SMT 6 | SMT 0 vs SMT 12 | SMT 0 vs SMT 18 | |
| Pain unpleasantness (0-100 scale) | ||||||||
| 0 wk | 41.7 (19.5) | 41.1 (21.1) | 40.3 (22.8) | 42.4 (22.2) | ||||
| 6 wk | 24.7 (21.7) | 20.3 (17.5) | 15.6 (17.3) | 18.4 (18.1) | 2.4 (0.9, 4.0)* | 4.2 (−0.8, 9.1) | 8.7 (3.5, 14.0)* | 6.6(1.7, 11.6)* |
| 12 wk | 29.7 (22.3) | 24.5 (20.6) | 22.2 (22.3) | 23.9 (21.3) | 2.0 (0.2, 3.7) | 4.8 (−1.0, 10.5) | 7.1 (1.1, 13.0)* | 5.8 (0.1, 11.5) |
| 18 wk | 26.8 (22.3) | 21.9 (21.2) | 20.4 (20.4) | 21.3 (21.8) | 1.8 (0.1, 3.6,) | 4.6 (−1.0, 10.3) | 5.8 (0.4, 11.2) | 5.8 (0.4, 11.2) |
| 24 wk | 27.4 (21.7) | 24.8 (21.8) | 25.0 (21.9) | 24.8 (22.4) | 0.7 (−1.1, 2.5) | 2.1 (−3.5, 7.8) | 2.0 (−3.6, 7.5) | 2.5 (−3.2, 8.3) |
| 39 wk | 28.3 (21.6) | 25.5 (21.3) | 23.2 (20.8) | 23.0 (21.1) | 1.8 (0.1, 3.6) | 2.4 (−3.3, 8.2) | 4.8 (−0.6, 10.3) | 5.4 (−0.2, 10.9) |
| 52 wk | 27.8 (22.1) | 22.1 (21.7) | 24.0 (24.0) | 21.5 (19.9) | 1.7 (−0.1, 3.5) | 5.4 (−0.3, 11.2) | 3.7 (−2.4, 9.7) | 6.4 (0.7, 12.1) |
| Days with pain (last 4 wk) | ||||||||
| 0 wk | 24.8 (4.8) | 24.1 (5.5) | 23.3 (5.7) | 24.1 (4.6) | ||||
| 6 wk | 18.9 (10.0) | 17.6 (10.6) | 15.0 (10.1) | 16.3 (10.8) | 0.8 (−0.0, 1.7) | 0.9 (−1.8, 3.5) | 3.0 (0.3, 5.6) | 2.2 (−0.6, 4.9) |
| 12 wk | 18.1 (9.5) | 17.4 (9.2) | 15.5 (9.7) | 14.7 (10.2) | 1.1 (0.2, 1.9)* | 0.4 (−2.0, 2.8) | 1.9 (−0.7, 4.5) | 3.0 (0.5, 5.6)* |
| 18 wk | 17.4 (10.2) | 17.6 (10.3) | 15.5 (10.3) | 14.9 (10.6) | 0.8 (−0.0, 1.7) | −0.6 (−3.2, 2.1) | 1.2 (−1.5, 3.9) | 2.2 (−0.6, 4.9) |
| 24 wk | 16.9 (10.0) | 16.5 (10.3) | 15.4 (9.5) | 13.5 (9.6) | 1.0 (0.2, 1.8)* | 0.1 (−2.5, 2.7) | 0.7 (−1.8, 3.3) | 3.1 (0.5, 5.7)* |
| 39 wk | 17.7 (9.8) | 15.6 (9.9) | 15.1 (10.4) | 14.3 (10.6) | 0.9 (0.1, 1.7) | 1.7 (−0.8, 4.2) | 1.7 (−0.8, 4.3) | 3.0 (0.4, 5.6) |
| 52 wk | 17.0 (10.2) | 15.3 (10.3) | 14.0 (10.6) | 13.6 (10.4) | 1.0 (0.1, 1.8)* | 1.3 (−1.4, 3.9) | 2.1 (−0.7, 4.9) | 3.0 (0.3, 5.7) |
| Days with disability (last 4 wk) | ||||||||
| 0 wk | 7.4 (8.1) | 6.7 (7.5) | 6.8 (7.5) | 6.5 (7.2) | ||||
| 6 wk | 2.4 (5.5) | 1.6 (3.0) | 1.3 (2.7) | 1.2 (3.4) | 0.3 (−0.0, 0.7) | 0.8 (−0.4, 1.9) | 1.0 (−0.1, 2.2) | 1.1 (−0.1, 2.3) |
| 12 wk | 3.4 (5.9) | 2.6 (4.9) | 2.0 (3.3) | 2.3 (3.7) | 0.4 (−0.0, 0.7) | 0.6 (−0.7, 1.9) | 1.3 (0.0, 2.5) | 1.0 (−0.3, 2.2) |
| 18 wk | 2.1 (5.3) | 2.2 (5.0) | 1.8 (4.1) | 2.1 (4.9) | 0.1 (−0.4, 0.5) | −0.1 (−1.4, 1.3) | 0.3 (−0.9, 1.6) | 0.0 (−1.3, 1.4) |
| 24 wk | 3.5 (6.7) | 2.7 (5.1) | 2.8 (4.6) | 2.8 (4.2) | 0.1 (−0.3, 0.6) | 0.7 (−0.7, 2.1) | 0.6 (−0.8, 2.1) | 0.5 (−0.9, 1.9) |
| 39 wk | 2.8 (5.1) | 3.0 (5.5) | 2.4 (4.7) | 2.5 (4.8) | 0.1 (−0.3, 0.5) | −0.3 (−1.7, 1.1) | 0.4 (−0.9, 1.6) | 0.2 (−1.1, 1.5) |
| 52 wk | 3.4 (6.0) | 3.4 (6.9) | 1.9 (3.7) | 2.4 (4.7) | 0.4 (−0.1, 0.8) | −0.1 (−1.7, 1.4) | 1.5 (0.2, 2.8) | 0.8 (−0.6, 2.1) |
| Perceived pain change (6-pt Likert)† | ||||||||
| 6 wk | 3.7 (0.9) | 4.1 (0.9) | 4.3 (1.0) | 4.3 (1.0) | 0.1 (0.1, 0.2)* | 0.2 (−0.0, 0.5) | 0.4 (0.2, 0.7)* | 0.4 (0.1, 0.7)* |
| 12 wk | 3.7 (0.9) | 3.8 (0.9) | 4.0 (1.0) | 4.0 (0.9) | 0.1 (0.0, 0.2) | 0.1 (−0.1, 0.4) | 0.3 (−0.0, 0.5) | 0.3 (0.0, 0.5) |
| 18 wk | 3.7 (0.9) | 4.0 (1.0) | 4.1 (1.0) | 4.0 (1.0) | 0.1 (−0.0, 0.2) | 0.2 (−0.0, 0.5) | 0.4 (0.1, 0.7)* | 0.2 (−0.0, 0.5) |
| 24 wk | 3.8 (1.0) | 3.9 (1.0) | 3.9 (1.0) | 3.9 (1.0) | 0.0 (−0.1, 0.1) | 0.1 (−0.2, 0.4) | 0.1 (−0.2, 0.4) | 0.1 (−0.2, 0.3) |
| 39 wk | 3.7 (1.0) | 3.8 (1.1) | 4.0 (1.0) | 4.0 (0.9) | 0.1 (0.0, 0.2) | 0.1 (−0.2, 0.4) | 0.3 (0.0, 0.6) | 0.3 (0.0, 0.5) |
| 52 wk | 3.7 (0.9) | 4.0 (1.1) | 3.9 (1.1) | 4.0 (0.9) | 0.1 (−0.0, 0.1) | 0.3 (0.0, 0.6) | 0.2 (−0.1, 0.5) | 0.2 (−0.0, 0.5) |
| Perceived disability change (6-pt Likert)† | ||||||||
| 6 wk | 3.6 (0.9) | 3.9 (0.9) | 4.0 (1.0) | 4.0 (0.9) | 0.1 (0.0, 0.2)* | 0.3 (0.0, 0.5) | 0.4 (0.1, 0.6)* | 0.4 (0.2, 0.6)* |
| 12 wk | 3.5 (0.9) | 3.8 (0.9) | 3.8 (1.0) | 3.8 (0.9) | 0.1 (0.0, 0.2)* | 0.2 (0.0, 0.5) | 0.3 (0.0, 0.5) | 0.3 (0.0, 0.5) |
| 18 wk | 3.6 (0.8) | 3.7 (1.0) | 3.8 (1.0) | 3.8 (0.9) | 0.1 (−0.0, 0.2) | 0.1 (−0.2, 0.3) | 0.2 (−0.1, 0.4) | 0.2 (−0.0, 0.5) |
| 24 wk | 3.6 (0.9) | 3.7 (0.9) | 3.7 (0.9) | 3.7 (1.0) | 0.0 (−0.1, 0.1) | 0.1 (−0.2, 0.3) | 0.1 (−0.2, 0.3) | 0.1 (−0.2, 0.4) |
| 39 wk | 3.6 (0.9) | 3.7 (1.0) | 3.9 (1.0) | 3.9 (0.9) | 0.1 (0.0, 0.2)* | 0.1 (−0.2, 0.4) | 0.3 (0.1, 0.6)* | 0.3 (0.0, 0.5)* |
| 52 wk | 3.6 (0.9) | 3.8 (1.0) | 3.8 (1.1) | 3.9 (0.9) | 0.1 (−0.0, 0.2) | 0.2 (−0.0, 0.5) | 0.2 (−0.1, 0.5) | 0.3 (0.0, 0.3) |
| SF-12 physical health component | ||||||||
| 0 wk | 43.0 (9.5) | 43.8 (8.9) | 44.3 (8.4) | 42.3 (8.8) | ||||
| 12 wk | 45.5 (10.3) | 47.1 (8.2) | 49.6 (8.5) | 47.5 (8.5) | 1.0 (0.3, 1.6)* | 1.2 (−0.8, 3.3) | 3.5 (1.3, 5.7)* | 2.4 (0.3, 4.6) |
| 24 wk | 50.0 (11.1) | 50.5 (10.1) | 51.4 (9.1) | 50.9 (9.4) | 0.5 (−0.3, 1.2) | 0.0 (−2.3, 2.4) | 0.8 (−1.6, 3.2) | 1.3 (−1.1, 3.6) |
| 39 wk | 50.6 (11.5) | 51.1 (10.3) | 52.7 (9.6) | 51.8 (9.3) | 0.6 (−0.2, 1.4) | 0.1 (−2.3, 2.4) | 1.5 (−0.9, 4.0) | 1.6 (−0.9, 4.0) |
| 52 wk | 50.7 (12.0) | 50.8 (11.0) | 52.6 (10.3) | 52.5 (8.5) | 0.8 (0.1, 1.6) | 0.3 (−2.7, 2.1) | 1.4 (−1.2, 4.0) | 2.2 (−0.2, 4.5) |
| SF-12 mental health component | ||||||||
| 0 wk | 50.2 (10.5) | 48.6 (10.5) | 47.6 (11.2) | 49.4 (9.6) | ||||
| 12 wk | 50.2 (10.8) | 50.4 (9.4) | 47.8 (11.0) | 48.0 (9.8) | −0.7 (−1.3, −0.0) | 1.3 (−0.7, 3.3) | −0.5 (−2.6, 1.5) | −1.5 (−3.5, 0.4) |
| 24 wk | 51.8 (10.9) | 52.8 (10.2) | 50.8 (11.8) | 51.3 (11.2) | −0.1 (−0.8, 0.6) | 2.1 (−0.0, 4.2) | 0.7 (−1.3, 2.8) | 0.1 (−2.1, 2.2) |
| 39 wk | 51.7 (11.3) | 51.5 (11.6) | 49.2 (13.6) | 49.0 (11.7) | −0.8 (−1.5, −0.0) | 1.1 (−1.3, 3.4) | −0.4 (−2.9, 2.1) | −2.0 (−4.3, 0.3) |
| 52 wk | 51.3 (12.0) | 50.4 (11.4) | 50.6 (12.7) | 50.4 (11.7) | −0.0 (−0.8, 0.8) | 0.2 (−2.3, 2.7) | 1.1 (−1.6, 3.7) | −0.3 (−2.9, 2.3) |
| EuroQol Health State (0-100 scale) | ||||||||
| 0 wk | 70.1 (17.2) | 72.1 (13.8) | 73.5 (14.4) | 68.2 (17.4) | ||||
| 12 wk | 73.5 (17.3) | 78.4 (14.1) | 77.9 (15.0) | 75.7 (14.5) | 0.8 (−0.4, 2.0) | 3.9 (0.0, 7.7) | 2.7 (−1.3, 6.7) | 3.1 (−0.8, 6.9) |
| 24 wk | 73.9 (17.5) | 77.8 (15.5) | 77.0 (15.4) | 74.5 (16.7) | 0.3 (−1.0, 1.6) | 2.9 (−1.0, 6.9) | 1.4 (−2.6, 5.5) | 1.5 (−2.7, 5.8) |
| 39 wk | 73.1 (20.0) | 76.8 (17.2) | 76.6 (15.6) | 75.3 (16.8) | 0.9 (−0.5, 2.3) | 2.6 (−1.9, 7.0) | 1.8 (−2.6, 6.2) | 3.2 (−1.3, 7.6) |
| 52 wk | 74.8 (17.0) | 77.1 (17.0) | 77.3 (15.3) | 77.2 (14.9) | 1.0 (−0.3, 2.2) | 1.3 (−2.7, 5.4) | 0.9 (−3.1, 4.9) | 3.3 (−0.5, 7.2) |
| Non-prescription medication (times in last 4 wk) | ||||||||
| 0 wk | 7.6 (10.0) | 8.9 (10.8) | 9.5 (10.0) | 7.6 (9.4) | ||||
| 6 wk | 4.3 (6.8) | 4.1 (6.9) | 4.0 (6.7) | 4.0 (8.3) | 0.1 (−0.5, 0.7) | 0.6 (−1.2, 2.4) | 0.9 (−0.8, 2.6) | 0.3 (−1.5, 2.1) |
| 12 wk | 7.8 (11.0) | 7.1 (23.0) | 5.8 (7.6) | 7.8 (25.8) | 0.1 (−1.6, 1.8) | 1.4 (−2.7, 5.6) | 3.2 (0.4, 5.9)* | −0.1 (−5.5, 5.3) |
| 18 wk | 5.7 (7.4) | 6.0 (10.4) | 5.3 (9.1) | 5.5 (9.1) | 0.2 (−0.5, 0.8) | 0.1 (−2.4, 2.6) | 1.0 (−1.1, 3.2) | 0.2 (−1.8, 2.2) |
| 24 wk | 8.1 (13.7) | 7.7 (15.8) | 6.5 (8.6) | 6.4 (10.8) | 0.7 (−0.4, 1.7) | 0.9 (−3.3, 5.1) | 2.4 (−0.7, 5.5) | 1.8 (−1.5, 5.0) |
| 39 wk | 7.2 (14.2) | 7.4 (12.2) | 6.6 (8.9) | 7.7 (13.5) | −0.0 (−1.1, 1.1) | 0.3 (−3.4, 4.0) | 1.4 (−1.9, 4.7) | −0.5 (−4.0, 3.1) |
| 52 wk | 6.5 (8.0) | 6.6 (13.7) | 6.7 (9.3) | 6.8 (12.7) | −0.1 (−0.9, 0.8) | 0.3 (−2.7, 3.4) | 0.6 (−1.5, 2.6) | −0.3 (−2.9, 2.4) |
SMT, spinal manipulative therapy group.
Unadjusted group means are from original data without imputation; slopes and group differences are computed from imputed data adjusted for the baseline covariates. Positive signs of slopes and mean differences were computed to favor higher doses of SMT.
*
P < .025
†
Likert scale: much worse = 1, worse = 2, about the same = 3, better = 4, much better = 5, and completely recovered = 6.