Table 1.
Baseline Characteristics of Trial Participants
| Demographics | No.(%) | |||
|---|---|---|---|---|
| Placebo (n=50) |
Naltrexone (n=50) |
Overall (n=100) |
||
| Age, mean (SD), y | 42.4 (9.0) | 43.9 (8.1) | 43.2 (8.5) | |
| Race/Ethnicity | White | 28 (56.0) | 27 (54.0) | 55 (55.0) |
| African-American | 8 (16.0) | 11 (22.0) | 19 (19.0) | |
| Latino | 9 (18.0) | 9 (18.0) | 18 (18.0) | |
| Asian and Pacific Islander | 3 (6.0) | 1 (2.0) | 4 (4.0) | |
| Other | 2 (4.0) | 2 (4.0) | 4 (4.0) | |
| Current Gender Identity | Male | 47 (94) | 49 (47) | 96 (96) |
| Transgender Female (Male to Female) | 2 (4) | 1 (2) | 3 (3) | |
| Transgender Male (Female to Male) | 1 (2) | 0 (0) | 1 (1) | |
| Education | High school or less | 17 (34.0) | 9 (18.0) | 26 (26.0) |
| Some college | 19 (38.0) | 28 (56.0) | 47 (47.0) | |
| College or above | 14 (28.0) | 12 (24.0) | 26 (26.0) | |
| Income | under $20,000 | 29 (58.0) | 31 (62.0) | 60 (60.0) |
| $20,000–39,999 | 10 (20.0) | 10 (20.0) | 20 (20.0) | |
| $40,000 and above | 11 (22.0) | 8 (16.0) | 19 (19.0) | |
| Employment status | Not employed | 37 (74.0) | 33 (66.0) | 70 (70.0) |
| Part-time | 6 (12.0) | 9 (18.0) | 15 (15.0) | |
| Full-time | 6 (12.0) | 8 (16.0) | 14 (14.0) | |
| Methamphetamine use | ||||
| Frequency of methamphetamine use (past 4 weeks) ‡ | Two days or less per week | 20 (40.0) | 11 (22.0) | 31 (31.0) |
| Three - Seven days per week | 29 (58.0) | 39 (78.0) | 68 (68.0) | |
| Methamphetamine use during sex (past 4 weeks) ‡ | 50% or less of the time | 26 (52.0) | 10 (20.0) | 36 (36.0) |
| Greater than 50% of time | 23 (46.0) | 40 (80.0) | 63 (63.0) | |
| Route of methamphetamine administration | Injection | 25 (50.0) | 26 (52.0) | 51 (51.0) |
| Inserted rectally ‡ | 8 (16.0) | 21 (42.0) | 29 (29.0) | |
| Snorted | 14 (28.0) | 17 (34.0) | 31 (31.0) | |
| Smoked | 40 (80.0) | 42 (84.0) | 82 (82.0) | |
| Ingested orally | 4 (8.0) | 10 (20.0) | 14 (14.0) | |
| Methamphetamine severity of dependence scale (SDS) score, mean (SD) | 5.7 (3.2) | 6.3 (3.4) | 6.0 (3.3) | |
| Methamphetamine visual analog scale (VAS) craving score, mean (SD) | 50.3 (31.0) | 47.8 (30.5) | 49 (30.6) | |
| History of methamphetamine self-help or treatment program | 30 (60.0) | 28 (52.0) | 58 (58.0) | |
| Clinical | ||||
| HIV positive OPRM1 A118G Genotype | 37 (74.0) | 37 (74.0) | 74 (74.0) | |
| Heterozygous (AG) | 12 (24.0) | 13 (26.0) | 25 (50.0) | |
| Homozygous (Wild Type - AA) | 22 (44.0) | 24 (48.0) | 46 (92.0) | |
| Mutant (GG) | 0 0 | 1 (2.0) | 1 (2.0) | |
| Has regular health care provider | 44 (88.0) | 44 (88.0) | 88 (88.0) | |
| Has health insurance | 44 (88.0) | 49 (98.0) | 93 (310.0) | |
| Center for epidemiologic studies depression scale (CES-D) score, mean (SD) | 19.4 (12.1) | 19.4 (13.2) | 19.2 (12.6) | |
‡
characteristics with P<0.10 between treatment arms when compared using the Fisher exact test, and Wilcoxon rank sum tests, as appropriate.