Table 1.
Participant characteristics.
| Variable | Total sample | Ages 18–49 years | Ages ≥ 50 years | ||||
|---|---|---|---|---|---|---|---|
| (n = 469) | (n = 350) | (n = 119) | |||||
| Frequency | Range | Frequency | Range | Frequency | Range | p-value | |
| Age (N = 469), mean, (SD) | 41.04 (11.6) | 20–70 | 35.52 (7.1) | 20–49 | 57.29 (5.38) | 50–70 | |
| Age group, no. (%) | |||||||
| Less than 50 years | 350 (74.6) | ||||||
| 50 years and older | 119 (25.4) | ||||||
| Gender (N = 462), no. (%) | |||||||
| Man/male | 256 (55.4) | 187 (54.2) | 69 (59.0) | ||||
| Woman/female | 204 (44.2) | 156 (45.2) | 48 (41.0) | ||||
| Gender nonconforming | 2 (0.4) | 2 (0.6) | 0 (0.0) | ||||
| Race (N = 425), no. (%) | |||||||
| American Indian/Alaskan native | 13 (3.1) | 5 (1.6) | 8 (7.6) | ||||
| Black or African American | 14 (3.3) | 4 (1.3) | 10 (9.5) | ||||
| Native Hawaiian or other pacific Islander | 5 (1.2) | 5 (1.6) | 0 (0.0) | ||||
| Asian | 1 (0.2) | 1 (0.3) | 0 (0.0) | ||||
| White | 374 (88.0) | 291 (90.9) | 83 (79.0) | ||||
| Multiracial | 18 (4.2) | 14 (4.4) | 4 (3.8) | ||||
| Ethnicity (N = 377), no. (%) | |||||||
| Hispanic/Latino | 51 (13.5) | 37 (12.9) | 14 (15.4) | ||||
| Non-Hispanic/Latino | 326 (86.5) | 249 (87.1) | 77 (84.6) | ||||
| Employment status (N = 462), no. (%) | |||||||
| Unemployed | 165 (35.7) | 132 (38.2) | 33 (28.4) | ||||
| Part-time | 77 (16.7) | 62 (17.9) | 15 (12.9) | ||||
| Full-time | 106 (22.9) | 98 (28.3) | 8 (6.9) | ||||
| On disability | 114 (24.7) | 54 (15.6) | 60 (51.7) | ||||
| Reason for entering treatment (N = 452), no. (%) | |||||||
| Painkillers then heroin | 284 (62.8) | 235 (67.9) | 49 (46.2) | ||||
| Heroin then painkillers | 32 (7.1) | 17 (4.9) | 15 (14.2) | ||||
| Heroin only | 85 (18.8) | 59 (17.1) | 26 (24.5) | ||||
| Painkillers only | 43 (9.5) | 35 (10.1) | 8 (7.5) | ||||
| Pain only (no SUD) | 8 (1.8) | 0 (0.0) | 8 (7.5) | ||||
| Age at first use (N = 422), mean, (SD) | 22.91 (8.7) | 8–60 | 21.27 (6.4) | 10–47 | 28.51 (12.4) | 8–60 | |
| Pain severitya (N = 443), mean, (SD) | 4.56 (2.9) | 0–10 | 4.31 (2.8) | 0–10 | 5.36 (3.0) | 0–10 | 0.001 |
| Pain interferenceb (N = 447), mean, (SD) | 3.95 (3.1) | 0–10 | 3.51 (2.9) | 0–10 | 5.35 (3.2) | 0–10 | <0.001 |
| Self-rated healthc (N = 442), mean, (SD) | 3.33 (0.9) | 1–5 | 3.24 (0.9) | 1–5 | 3.60 (1.0) | 1–5 | <0.001 |
| Past 6-month physical activityd (N = 396), no. (%) | 0.019 | ||||||
| Hardly any physical activity | 43 (10.9) | 30 (9.7) | 13 (14.9) | ||||
| Mostly sitting, sometimes a walk or light gardening | 52 (13.1) | 38 (12.3) | 14 (16.1) | ||||
| Light physical exercise around 2–4 h/week | 100 (25.3) | 76 (24.6) | 24 (27.6) | ||||
| Moderate exercise 1–2 h/week, or > 4 h of light activity | 108 (27.3) | 87 (28.2) | 21 (24.1) | ||||
| Moderate exercise at least 3 h/week | 50 (12.6) | 40 (12.9) | 10 (11.5) | ||||
| Hard or very hard exercise regularly and several times/week | 43 (10.9) | 38 (12.3) | 5 (5.7) | ||||
| Total depression and anxiety scoree (N = 414), mean, (SD) | 5.32 (3.7) | 0–12 | 5.30 (3.8) | 0–12 | 5.41 (3.4) | 0–12 | 0.792 |
| Depression scoref (N = 418), mean, (SD) | 2.62 (1.9) | 0–6 | 2.58 (2.0) | 0–6 | 2.74 (1.9) | 0–6 | 0.471 |
| Anxiety scoreg (N = 430), mean, (SD) | 2.71 (2.0) | 0–6 | 2.73 (2.1) | 0–6 | 2.65 (1.9) | 0–6 | 0.753 |
SUD = substance use disorder. aPain Severity was measured using the West Haven-Yale Multidimensional Pain Inventory and scores range from 0 (no pain) to 10 (most intense). bPain Interference was also measured using the West Haven-Yale Multidimensional Pain Inventory and scores range from 0 (none) to 10 (extreme interference). cSelf-rated Health was measured from a single item where scores ranged from 1 (excellent) to 5 (poor). dPast 6-Month Physical Activity was measured using the 6-level Physical Activity Scale where scores ranged from 1 (hardly any physical activity) to 6 (hard or very hard exercise regularly and several times a week). Responses of 4–6 correspond to the World Health Organization’s recommended levels of activity. eTotal Depression and Anxiety score was measured using the four-item Patient Health Questionnaire (PHQ-4) for anxiety and depression. Total score is determined by adding together the scores of each of the 4 items. Scores are rated as normal (0–2), mild (3-5), moderate (6-8), and severe (9-12). f,gDepression and Anxiety scores were also separately calculated based on individual items from the PHQ-4; total scores of ≥ 3 for either suggest depression or anxiety, respectively.