Table 2. Baseline Characteristics of PREEMPT Study Participants by Treatment Group.
| Characteristic | Overall (n = 215) |
Intervention (n = 108) |
Control (n = 107) |
|---|---|---|---|
| Sex, No. (%) | |||
| Male | 113 (53) | 58 (54) | 55 (51) |
| Female | 102 (47) | 50 (46) | 52 (49) |
| Age, mean (SD), y | 55.5 (11.1) | 55.4 (10.8) | 55.6 (11.5) |
| Race, No. (%) | |||
| White | 155 (74) | 75 (69) | 80 (78) |
| Black or African American | 27 (13) | 12 (11) | 15 (15) |
| Asian | 12 (6) | 8 (7) | 4 (4) |
| Other | 17 (8) | 13 (12) | 4 (4) |
| Latino, No. (%) | 24 (11) | 16 (15) | 8 (8) |
| Marital status, No. (%) | |||
| Married or living with partner | 142 (67) | 75 (69) | 67 (65) |
| Widowed | 10 (5) | 5 (5) | 5 (5) |
| Divorced or separated | 43 (20) | 21 (19) | 22 (21) |
| Never married | 16 (8) | 7 (7) | 9 (9) |
| Education, No. (%) | |||
| High school diploma or less | 16 (7) | 6 (6) | 10 (9) |
| Some college and/or associate degree and/or vocational training | 103 (48) | 54 (50) | 49 (46) |
| Bachelor’s degree | 56 (26) | 23 (21) | 33 (31) |
| Master’s or doctoral or professional degree | 40 (19) | 25 (23) | 15 (14) |
| Employment, No. (%) | |||
| Full time (≥35 h/wk) | 85 (40) | 40 (37) | 45 (42) |
| Part time (<35 h/wk) | 18 (8) | 12 (11) | 6 (6) |
| Not employed or retired or unable to work | 112 (52) | 56 (52) | 56 (52) |
| Practice location, No. (%) | |||
| UC Davis and/or Primary Care Network | 110 (51) | 56 (52) | 54 (51) |
| VANCHCS or David Grant, Travis AFB | 105 (49) | 52 (48) | 53 (49) |
| Pain diagnosis, No. (%) | |||
| Axial | 90 (42) | 42 (39) | 48 (45) |
| Extremity | 84 (39) | 45 (42) | 39 (36) |
| Other or unknown | 41 (19) | 21 (19) | 20 (19) |
| PEG scorea | 6.0 (1.9) | 5.8 (2.0) | 6.1 (1.8) |
| Baseline opioid use, No. (%)b | 86 (45) | 41 (42) | 45 (48) |
| Primary and secondary outcome scores, mean (SD)c | |||
| Pain interferenced,e | 64.3 (5.8) | 64.0 (5.9) | 64.7 (5.8) |
| Pain intensityf | 53.7 (5.2) | 53.5 (5.4) | 53.8 (5.1) |
| Global physical healthg | 41.6 (6.2) | 42.5 (6.8) | 40.6 (5.5)h |
| Global mental healthi | 44.1 (8.6) | 44.9 (9.1) | 43.2 (7.9) |
| Analgesic adherence (overuse)j | 89.8 (12.9) | 90.2 (12.4) | 89.4 (13.4) |
| Analgesic adherence (underuse)k | 75.4 (23.4) | 75.2 (22.3) | 75.6 (24.6) |
| Trust in clinicianl | 76.1 (16.4) | 76.8 (15.8) | 75.3 (17.1) |
| Satisfaction with pain informationm | 50.6 (38.2) | 50.5 (38.8) | 50.7 (37.8) |
| Satisfaction with medical caren | 82.2 (17.7) | 84.7 (15.7) | 79.5 (19.2) h |
| Satisfaction with pain medicationo | 64.4 (22.8) | 65.2 (22.1) | 63.4 (23.6) |
| Medication-related shared decision-makingp | 74.6 (23.9) | 74.3 (23.8) | 75.0 (24.3) |
Abbreviations: AFB, air force base; PEG, pain, enjoyment, general activity; PREEMPT, Personalized Research for Monitoring Pain Treatment; PROMIS, Patient-Reported Outcomes Measurement Information System; UC Davis, University of California, Davis; VANCHCS, Veterans Affairs, Northern California Health Care System.
In contrast to other measures, which were obtained at the baseline visit, PEG scores were obtained at screening. Mean scores were clinically comparable and statistically nonsignificant (P = .31).
Baseline opioid use was assessed via medical record review among patients who provided permission for such review (n = 190 total; 97 in the intervention group and 93 in control).
All scales had a theoretical range of 0 to 100 except for PEG (range, 0-10); in all cases 0 was the best possible score.
Primary outcome.
PROMIS pain-interference scores in this sample ranged from 50.3 to 77.0. The possible range, based on the raw score to T-score conversion table in the PROMIS Pain Interference Scoring Manual (https://www.assessmentcenter.net/manuals.aspx), is 41.0 to 78.3. Higher scores indicate greater pain interference.
PROMIS pain intensity scores in this sample ranged from 40.5 to 69.4. Higher scores indicate greater pain intensity.
PROMIS global physical health scores in this sample ranged from 23.7 to 62.5. Higher scores indicate better physical health.
Mean differences between n-of-1 and control groups, P < .05.
PROMIS global mental health scores in this sample ranged from 21.3 to 63.6. Higher scores indicate better mental health.
Scores in this sample ranged from 37.5 to 100. Higher scores indicate greater adherence and less overuse of medication.
Scores in this sample ranged from 0 to 100. Higher scores indicate greater adherence and less underuse of medication.
Scores in this sample ranged from 20.5 to 100. Higher scores indicate greater trust.
Scores in this sample ranged from 0 to 100. Higher scores indicate greater satisfaction.
Scores in this sample ranged from 15 to 100. Higher scores indicate greater satisfaction.
Scores in this sample ranged from 0 to 100. Higher scores indicate greater satisfaction.
Medication-related shared decision-making scores, which were computed only for patients who reported discussing medications with their clinician in the past 12 mo, ranged from 0 to 100 in this sample. Higher scores indicate more shared decision making.