Table 1.
Baseline Characteristics of PREEMPT Study Participants with Medical Record Abstraction by Treatment Group
| Characteristic | Overall (N = 190) n (%) |
N-of-1 (N = 97) n (%) |
Control (N = 93) n (%) |
|---|---|---|---|
| Age, mean (SD), years | 55.4 (11.0) | 55.5 (12.0) | 55.3 (10.1) |
| Gender | |||
| Male | 100 (52.6%) | 52 (53.6%) | 48 (51.6%) |
| Female | 90 (47.4%) | 45 (46.4%) | 45 (48.4%) |
| Marital status | |||
| Married/living with partner | 128 (67.4%) | 67 (69.1%) | 61 (65.6%) |
| Widowed | 9 (4.7%) | 4 (4.1%) | 5 (5.4%) |
| Separated/divorced | 37 (19.5%) | 19 (19.6%) | 18 (19.4%) |
| Never married | 16 (8.4%) | 7 (7.2%) | 9 (9.7%) |
| Race* | |||
| White | 136 (71.6%) | 64 (66.0%) | 72 (77.4%) |
| Black/African American | 25 (13.2%) | 12 (12.4%) | 13 (14.0%) |
| Asian | 12 (6.3%) | 8 (8.3%) | 4 (4.3%) |
| Other | 17 (9.0%) | 13 (13.4%) | 4 (4.3%) |
| Latino/Hispanic | 21 (11.1%) | 13 (13.5%) | 8 (8.6%) |
| Education | |||
| Some HS, no diploma/completed HS or GED | 15 (7.9%) | 4 (4.1%) | 11 (11.8%) |
| Some college/associate degree/vocational training | 94 (23.2%) | 50 (51.6%) | 44 (47.3%) |
| Bachelor degree | 47 (24.7%) | 27 (27.8%) | 20 (21.5%) |
| Master/doctoral/professional degree | 34 (17.9%) | 16 (16.5%) | 18 (19.4%) |
| Employment | |||
| Full time | 80 (42.1%) | 41 (42.3%) | 39 (41.9%) |
| Part time | 15 (7.9%) | 7 (7.2%) | 8 (8.6%) |
| Retired/unable/not employed | 95 (50.0%) | 49 (50.5%) | 46 (49.5%) |
| Site | |||
| UC Davis/Primary Care Network (PCN) | 103 (54.2%) | 52 (53.6%) | 51 (54.8%) |
| Veterans Administration | 87 (45.8%) | 45 (46.4%) | 42 (45.2%) |
| Tobacco smoking | |||
| Current | 14 (7.4%) | 10 (10.3%) | 4 (4.3%) |
| Former | 70 (36.8%) | 32 (33.0%) | 38 (40.9%) |
| Never | 106 (55.8%) | 55 (56.7%) | 51 (54.8%) |
| Alcohol problem | |||
| Current (diagnosis of alcoholism or problem drinking, or ≥ 3 drinks/day) | 3 (1.6%) | 2 (2.1%) | 1 (1.1%) |
| Former | 14 (7.4%) | 5 (5.2%) | 9 (9.7%) |
| Never | 173 (91.1%) | 90 (92.8%) | 83 (89.3%) |
| Pain category† | |||
| Mechanical | 166 (87.4%) | 83 (85.6%) | 83 (89.3%) |
| Fibromyalgia* | 8 (4.2%) | 2 (2.1%) | 6 (6.5%) |
| Inflammatory | 4 (2.1%) | 3 (3.1%) | 1 (1.1%) |
| Neuropathic | 28 (14.7%) | 15 (15.5%) | 13 (14.0%) |
| Pain intensity at baseline, mean (SD) | 53.5 (5.2) | 53.6 (5.4) | 53.5 (5.0) |
| Pain intensity at 6 months follow-up, mean (SD) | 51.3 (6.0) | 50.5 (6.6) | 52.2 (5.2) |
| Baseline opioid use (any use) | 86 (45.3%) | 41 (42.3%) | 45 (48.4%) |
| Baseline opioid use, mean MME (SD) | 13.3 (28.0) | 13.1 (29.9) | 13.4 (26.1) |
| Baseline NSAID use‡ | 81 (42.6%) | 49 (50.5%) | 32 (34.4%) |
| Active medical diagnoses | |||
| Sleep apnea | 38 (20.0) | 19 (19.6%) | 19 (20.4%) |
| COPD* | 9 (4.7%) | 7 (7.2%) | 2 (2.2%) |
| History of peptic ulcer disease/GI bleeding past 5 years* | 2 (1.1%) | 0 | 2 (2.2%) |
| Chronic kidney disease (CKD stage III or greater) | 8 (4.2%) | 6 (6.2%) | 2 (2.2%) |
| Congestive heart failure | 7 (3.7%) | 5 (5.2%) | 2 (2.2%) |
| Diabetes | 36 (19.0%) | 21 (21.7%) | 15 (16.1%) |
| Active psychiatric diagnoses | |||
| Depression | 60 (31.6%) | 32 (33.0%) | 28 (30.1%) |
| PTSD | 23 (12.1%) | 11 (11.3%) | 12 (12.9%) |
| Insomnia | 29 (15.3%) | 14 (14.4%) | 15 (16.1%) |
| Other anxiety disorder | 26 (13.7%) | 12 (12.4%) | 14 (15.1%) |
| Concomitant Medications | |||
| Benzodiazepines (any dose)‡ | 22 (11.6%) | 7 (7.2%) | 15 (16.1%) |
| Aspirin or anticoagulant therapy | 44 (23.2%) | 21 (21.7%) | 23 (24.7%) |
*Differences between N-of-1 and control group, 0.05 < p < 0.1
†Patients could be classified with more than one category of pain
‡Differences between N-of-1 and control group, p < 0.05