Table 1. Baseline characteristics.
| Oregon | Minnesota | SMT 0 (n = 64) | SMT 6 (n=65) | SMT 12 (n = 64) | SMT 18 (n = 63) | All (n=256) | |
|---|---|---|---|---|---|---|---|
| Sociodemographic information | |||||||
| Age (y) | 37 (12) | 45 (12) | 40 (12) | 40 (12) | 43 (13) | 42 (14) | 41 (13) |
| Female | 95 (74.2%) | 87 (68.0%) | 48 (75.0%) | 45 (69.2%) | 45 (70.3%) | 44 (69.8%) | 182 (71.1%) |
| White non-Hispanic | 104 (81.2%) | 110 (85.9%) | 53 (82.8%) | 58 (89.2%) | 51 (79.7%) | 52 (82.5%) | 214 (83.6%) |
| Married or living together | 66 (51.6%) | 92 (71.9%) | 39 (60.9%) | 34 (52.3%) | 42 (65.6%) | 43 (68.3%) | 158 (61.7%) |
| College graduate | 86 (67.2%) | 85 (66.4%) | 36 (56.2%) | 46 (70.8%) | 41 (64.1%) | 48 (76.2%) | 171 (66.8%) |
| Household income < $40,000 | 62 (48.4%) | 24 (19.2%) | 20 (31.7%) | 30 (46.9%) | 18 (28.6%) | 18 (28.6%) | 86 (34.0%) |
| Smoker | 11 (8.6%) | 10 (7.8%) | 6 (9.4%) | 5 (7.7%) | 5 (7.8%) | 5 (7.9%) | 21 (8.2%) |
| Confidence in treatment success (expectations) | |||||||
| Spinal manipulation (1–7 scale)* | 5.1 (1.1) | 5.0 (1.0) | 5.0 (1.1) | 5.0 (1.0) | 5.2 (1.2) | 5.1 (1.0) | 5.1 (1.1) |
| Light massage ((1–7 scale)* | 4.8 (1.4) | 4.8 (1.2) | 4.9 (1.2) | 4.7 (1.3) | 4.9 (1.4) | 4.8 (1.4) | 4.8 (1.3) |
| Difference (manipulation – light massage) | 0.3 (1.6) | 0.2 (1.2) | 0.1 (1.5) | 0.3 (1.4) | 0.4 (1.5) | 0.3 (1.3) | 0.3 (1.4) |
| Physical activity (Minutes / day) | 86 (106) | 85 (120) | 95 (130) | 69 (85) | 69 (85) | 99 (143) | 85 (113) |
| (Days / wk) | 5.4 (1.5) | 5.2 (1.7) | 5.3 (1.5) | 5.3 (1.6) | 5.4 (1.6) | 5.1 (1.7) | 5.3 (1.6) |
| Previous care for CGH | |||||||
| Chiropractic | 67 (52.3%) | 59 (46.1%) | 29 (45.3%) | 28 (43.1%) | 34 (53.1%) | 35 (55.6%) | 126 (49.2%) |
| Massage | 60 (46.9%) | 46 (35.9%) | 27 (42.2%) | 23 (35.4%) | 31 (48.4%) | 25 (39.7%) | 106 (41.4%) |
| Chiropractic or massage | 77 (60.2%) | 63 (49.2%) | 34 (53.1%) | 30 (46.2%) | 40 (62.5%) | 36 (57.1%) | 140 (54.7%) |
| Headache and neck complaint | |||||||
| Days with CGH ( last 4 wk) | 15.8 (6.7) | 15.3 (6.6) | 15.1 (6.3) | 15.2 (7.2) | 16.2 (6.9) | 15.8 (6.1) | 15.6 (6.6) |
| Average CGH pain intensity (0–10 scale)† | 4.5 (1.1) | 4.5 (1.1) | 4.4 (1.0) | 4.4 (1.0) | 4.5 (1.1) | 4.7 (1.1) | 4.5 (1.1) |
| CGH Duration (y) | 7.9 (8.0) | 6.7 (7.9) | 5.7 (6.4) | 8.1 (9.3) | 8.4 (8.5) | 6.9 (7.1) | 7.3 (7.9) |
| CGH-related disability (36–78)† | 58.7 (4.6) | 56.1 (4.9) | 58.5 (4.6) | 56.0 (5.2) | 57.2 (5.1) | 57.9 (4.4) | 57.4 (4.9) |
| Lost work due to CGH | |||||||
| 1/2 day or more | 69 (53.9%) | 36 (28.1%) | 25 (38.5%) | 26 (40.6%) | 27 (42.9%) | 69 (53.9%) | 105 (41.0%) |
| If yes, days with lost work (last 4 wk) | 2.0 (3.7) | 1.2 (4.3) | 1.4 (3.7) | 1.7 (4.6) | 1.8 (4.1) | 1.4 (3.8) | 1.6 (4.1) |
| Days with non-CGH headaches (last 4 wk) | 2.3 (2.7) | 2.3 (3.0) | 2.3 (3.1) | 2.4 (3.0) | 2.3 (2.4) | 2.2 (3.1) | 2.3 (2.9) |
| Days with neck pain (last 4 wk) | 18.8 (7.2) | 17.9 (7.8) | 19.2 (7.6) | 18.8 (7.2) | 18.2 (8.0) | 17.1 (7.3) | 18.3 (7.5) |
| Average neck pain intensity (0–10 scale)† | 4.6 (1.5) | 4.6 (1.5) | 4.5 (1.5) | 4.5 (1.4) | 4.5 (1.5) | 4.8 (1.5) | 4.6 (1.5) |
| Health Status | |||||||
| Tension Type Headache | 30 (23.4%) | 23 (18.0%) | 14 (21.9%) | 13 (20.0%) | 13 (20.3%) | 13 (20.6%) | 53 (20.7%) |
| Migraine | 31 (24.2%) | 25 (19.5%) | 14 (21.9%) | 15 (23.1%) | 14 (21.9%) | 13 (20.6%) | 56 (21.9%) |
| Lower back problems | 43 (33.6%) | 43 (33.6%) | 19 (29.7%) | 20 (30.8%) | 22 (34.4%) | 25 (39.7%) | 86 (33.6%) |
| Any back problems‡ | 70 (54.7%) | 70 (54.7%) | 37 (57.8%) | 32 (49.2%) | 35 (54.7%) | 36 (57.1%) | 140 (54.7%) |
| Any comorbidity‡ | 90 (70.3%) | 87 (68.0%) | 45 (70.3%) | 39 (60.0%) | 49 (76.6%) | 44 (69.8%) | 177 (69.1%) |
| EuroQol “Health State Today” (0–100 VAS)† | 74.4 (13.7) | 76.7 (13.2) | 74.9 (13.7) | 76.3 (11.3) | 76.1 (13.9) | 74.8 (15.0) | 75.5 (13.5) |
| Days taking medication for CGH (last 4 wk) | 6.3 (4.9) | 6.3 (4.6) | 5.6 (4.5) | 5.9 (4.0) | 6.6 (5.4) | 7.0 (4.8) | 6.3 (4.7) |
SMT, spinal manipulative therapy; CGH, cervicogenic headache; VAS, visual analog scale.
Values are mean (standard deviation) or number (percentage).
*
Seven-point Likert scale from extremely doubtful (1) to extremely confidence (7) in treatment success.
†
Lower scores are more favorable with the exception of the EuroQol VAS.
‡
Any back problems includes upper, middle, and lower back. Comorbidity includes any of the following: diabetes or arthritis, back, lung, cardiovascular, gastrointestinal, urinary, gynecological, or prostate problems.