Table 1.
Baseline demographic and clinical characteristics by treatment group (intention-to-treat).
| Characteristic | No. (%) | |||
|---|---|---|---|---|
| Total sample (n = 263) | Empowered Relief (n = 87) | Cognitive behavioral therapy (n = 88) | Health education (n = 88) | |
| Age, mean (SD), y | 47.9 (13.8) | 49.7 (15.0) | 45.9 (13.1) | 48.0 (13.2) |
| Sex | ||||
| Female | 131 (49.8) | 44 (50.6) | 40 (45.5) | 47 (53.4) |
| Male | 130 (49.4) | 42 (48.3) | 47 (53.4) | 41 (46.6) |
| Other | 2 (0.8) | 1 (1.1) | 1 (1.1) | 0 (0.0) |
| Race | ||||
| White | 157 (60.2) | 57 (66.3) | 48 (54.5) | 52 (59.8) |
| Asian/Pacific Islander | 64 (24.5) | 16 (18.6) | 27 (30.7) | 21 (24.1) |
| African American | 11 (4.2) | 5 (5.8) | 4 (4.5) | 2 (2.3) |
| American Indian/Alaska Native | 2 (0.8) | 1 (1.2) | 0 (0.0) | 1 (1.1) |
| Other | 27 (10.3) | 7 (8.1) | 9 (10.2) | 11 (12.6) |
| Ethnicity | ||||
| Hispanic | 17 (6.6) | 7 (8.3) | 6 (6.9) | 4 (4.6) |
| Non-Hispanic | 241 (93.4) | 77 (91.7) | 81 (93.1) | 83 (95.4) |
| Relationship status | ||||
| Married/cohabitating | 160 (60.8) | 53 (60.9) | 58 (65.9) | 49 (55.7) |
| Never married | 71 (27.0) | 27 (31.0) | 22 (25.0) | 22 (25.0) |
| Divorced | 22 (8.4) | 5 (5.7) | 4 (4.5) | 13 (14.8) |
| Separated | 6 (2.3) | 1 (1.1) | 1 (1.1) | 4 (4.5) |
| Widowed | 4 (1.5) | 1 (1.1) | 3 (3.4) | 0 (0.0) |
| Education | ||||
| High school | 6 (2.3) | 2 (2.3) | 2 (2.3) | 2 (2.3) |
| Some college | 66 (25.1) | 23 (26.4) | 17 (19.3) | 26 (29.5) |
| Bachelor's degree | 90 (34.2) | 30 (34.5) | 32 (36.4) | 28 (31.8) |
| Master's degree | 67 (25.5) | 21 (24.1) | 26 (29.5) | 20 (22.7) |
| Doctoral degree | 34 (12.9) | 11 (12.6) | 11 (12.5) | 12 (13.6) |
| Employment | ||||
| Full-time | 114 (43.3) | 30 (34.5) | 45 (51.1) | 39 (44.3) |
| Part-time | 49 (18.6) | 17 (19.5) | 14 (15.9) | 18 (20.5) |
| Retired | 39 (14.8) | 22 (25.3) | 9 (10.2) | 8 (9.1) |
| Student | 16 (6.1) | 6 (6.9) | 6 (6.8) | 4 (4.5) |
| Unemployed | 16 (6.1) | 4 (4.6) | 6 (6.8) | 6 (6.8) |
| Disabled | 13 (4.9) | 4 (4.6) | 4 (4.5) | 5 (5.7) |
| Household income, $USD | ||||
| <30,000 | 31 (12.3) | 14 (16.5) | 7 (8.5) | 10 (11.6) |
| <50,000 | 27 (10.7) | 9 (10.6) | 7 (8.5) | 11 (12.8) |
| <70,000 | 30 (11.9) | 12 (14.1) | 10 (12.2) | 8 (9.3) |
| ≥70,000 | 165 (65.2) | 50 (58.8) | 58 (70.7) | 57 (66.3) |
| Smoking status | ||||
| Never smoked | 175 (66.8) | 58 (66.7) | 65 (73.9) | 52 (59.8) |
| Current | 20 (7.6) | 5 (5.7) | 6 (6.8) | 9 (10.3) |
| Past | 67 (25.6) | 24 (27.6) | 17 (19.3) | 26 (29.9) |
| BMI, mean (SD), kg/m2 | 27.0 (6.3) | 27.3 (6.0) | 27.0 (6.5) | 26.7 (6.3) |
| Pain duration | ||||
| 6–12 mo | 14 (5.3) | 4 (4.6) | 8 (9.1) | 2 (2.3) |
| 1–5 y | 79 (30.0) | 25 (28.7) | 24 (27.3) | 30 (34.1) |
| >5 y | 170 (64.6) | 58 (66.7) | 56 (63.6) | 56 (63.6) |
| Back pain intensity, mean (SD) | ||||
| Past 30 d | 5.8 (1.3) | 5.6 (1.3) | 5.9 (1.3) | 6.0 (1.3) |
| Treatment expectations, mean (SD)* | ||||
| Positive | 3.69 (1.27) | 3.71 (1.30) | 3.74 (1.22) | 3.60 (1.32) |
| Negative | 2.14 (1.30) | 2.29 (1.34) | 2.00 (1.12) | 2.12 (1.43) |
| Comorbid pain condition† | ||||
| 1 | 127 (48.3) | 38 (43.7) | 43 (48.9) | 46 (52.3) |
| 2+ | 48 (18.3) | 18 (20.7) | 15 (17.0) | 15 (17.0) |
| Fibromyalgia | 10 (3.8) | 2 (2.3) | 4 (4.5) | 4 (4.5) |
| Complex regional pain syndrome | 3 (1.1) | 1 (1.1) | 0 (0.0) | 2 (2.3) |
| Pelvic pain | 22 (8.4) | 4 (4.6) | 9 (10.2) | 9 (10.2) |
| Migraine | 31 (11.8) | 13 (14.9) | 8 (9.1) | 10 (11.4) |
| Pain, other | 160 (60.8) | 54 (62.1) | 54 (61.4) | 52 (59.1) |
| Medication use for CLBP | ||||
| Opioids | 43 (16.3) | 13 (14.9) | 17 (19.3) | 13 (14.8) |
| NSAID/acetaminophen‡ | 123 (46.8) | 45 (51.7) | 38 (43.2) | 40 (45.5) |
| Adjunctive pain medications§ | 66 (25.1) | 22 (25.3) | 29 (33.0) | 15 (17.0) |
| Mental health disorders | ||||
| Mood disorders | ||||
| Ever | 132 (50.2) | 44 (50.6) | 44 (50.0) | 44 (50.0) |
| Current | 16 (6.1) | 9 (10.3) | 4 (4.5) | 3 (3.4) |
| Past | 131 (49.8) | 43 (49.4) | 44 (50.0) | 44 (50.0) |
| Anxiety disorders | 82 (31.2) | 24 (27.6) | 33 (37.5) | 25 (28.4) |
Wald χ2 test used for categorical variables; F-test used for continuous variables, P values all non-significant between groups.
*
Stanford Expectations of Treatment Scale (SETS).
†
Pain conditions comorbid with chronic low back pain, excluding post-surgical pain.
‡
Prescription and/or over-the-counter.
§
Neuropathic pain medication, muscle relaxant, and all other pain related medication (OTC or prescription).
BMI, body mass index; CLBP, chronic low back pain; OTC, over-the-counter.