Table 1.
Baseline Characteristics of Participants With Chronic Low Back Pain
| Characteristicsa | Facet Joint Trial | Sacroiliac Joint Trial | Combination Trial | |||
|---|---|---|---|---|---|---|
| Intervention (n = 125) | Control (n = 126) | Intervention (n = 116) | Control (n = 112) | Intervention (n = 103) | Control (n = 99) | |
| Age, mean (SD), y | 52.98 (11.48) | 52.60 (10.79) | 51.58 (10.94) | 51.13 (12.22) | 50.80 (11.33) | 53.31 (10.35) |
| Women, No. (%) | 65 (55.56) | 60 (51.72) | 87 (74.35) | 79 (75.96) | 64 (65.31) | 66 (74.15) |
| BMI, mean (SD) | 26.77 (5.17) | 27.62 (4.27) | 26.73 (4.17) | 26.76 (4.53) | 26.84 (3.82) | 26.43 (4.25) |
| Smoker, No. (%) | 34 (29.05) | 34 (29.05) | 29 (26.61) | 31 (29.81) | 23 (23.46) | 26 (29.21) |
| Education level, No. (%)b | ||||||
| Low | 57 (48.72) | 64 (55.17) | 59 (54.13) | 53 (50.96) | 52 (53.06) | 43 (48.31) |
| Moderate | 35 (29.99) | 34 (29.31) | 32 (29.36) | 32 (30.76) | 33 (33.67) | 32 (35.96) |
| High | 21 (17.95) | 16 (13.79) | 18 (16.51) | 18 (17.31) | 12 (12.24) | 14 (15.73) |
| Married or living with a partner, No. (%) | 93 (79.49) | 98 (84.48) | 85 (79.61) | 82 (79.61) | 66 (67.35) | 68 (76.40) |
| Having a paid job, No. (%) | 64 (54.70) | 66 (56.80) | 66 (60.55) | 50 (48.07) | 48 (48.97) | 44 (48.44) |
| History of back pain, median (IQR), mo | ||||||
| Time since first experience with low back pain | 146.00 (49.75-267.67) | 100.33 (36.5-186.30) | 97.33 (37.51-228.12) | 65.08 (27.08-144.21) | 120.58 (37.32-222.04) | 97.33 (32.33-192.58) |
| Time since first current episode with low back pain | 31.33 (12.17-103.42) | 26.73 (10.54-73.00) | 30.33 (12.17-76.03) | 24.33 (12.17-66.58) | 36.50 (12.17-121.67) | 32.33 (8.00-97.19) |
| Origin of back pain, No. | ||||||
| Facet and sacroiliac joint | 69 | 70 | ||||
| Facet and disc | 18 | 18 | ||||
| Sacroiliac joint and disc | 6 | 1 | ||||
| Facet and sacroiliac joint and disc | 3 | 6 | ||||
| Unknown | 7 | 4 | ||||
| CEQ score, mean (SD)c | ||||||
| Credibility | 21.36 (3.92) | 19.47 (5.49) | 21.36 (4.51) | 19.88 (5.31) | 20.10 (4.70) | 17.07 (5.99) |
| Expectancy | 18.97 (4.59) | 17.36 (5.20) | 18.75 (4.99) | 18.23 (5.31) | 16.88 (5.78) | 14.38 (6.24) |
| Pain intensity score in the past week, mean (SD)d | 7.14 (1.38) | 7. 19 (1.29) | 7.17 (1.65) | 7.06 (1.43) | 7.19 (1.43) | 7.43 (1.41) |
| Functioning score, mean (SD)e | 35.07 (14.66) | 34.39 (12.24) | 38.07 (14.07) | 33.70 (14.43) | 39.06 (14.03) | 37.20 (13.74) |
| Quality-of-life score, mean (SD)f | 0.52 (0.26) | 0.54 (0.26) | 0.50 (0.27) | 0.56 (0.27) | 0.49 (0.28) | 0.52 (0.28) |
aResults are presented of the 233 participants in the facet joint trial, 207 participants in the sacroiliac joint trial, and 187 participants in the combination trial who had complete baseline data.
bEducation levels: low indicates preschool, primary school, or lower secondary school; moderate indicates higher secondary school or undergraduate; high indicates tertiary, university, or postgraduate.
cA higher score indicates more credibility in the effectiveness of treatment or higher expectations about the treatment (score range, 0-27).
dMeasured by numeric rating scale (score range, 0-10); a higher score indicates more severe pain intensity.
eMeasured by Oswestry Disability Index (score range, 0-100); a higher score indicates worse functioning.
fMeasured by EuroQol-5D (score range, 0-1); a higher score indicates better quality of life.