TABLE 1.
Demographic and clinical characteristics examined as moderator variables among all patients randomly assigned to extended-release naltrexone or buprenorphine-naloxone (N=570)a
| Moderator Variable | Extended-Release Naltrexone (N=283) | Buprenorphine-Naloxone (N=287) | ||
|---|---|---|---|---|
|
| ||||
| N | % | N | % | |
| Male | 195 | 68.9 | 206 | 71.8 |
| Mean | SD | Mean | SD | |
|
| ||||
| Age (years) | 34.0 | 9.5 | 33.7 | 9.8 |
| N | % | N | % | |
|
| ||||
| Age ≤25 years | 49 | 17.3 | 62 | 21.6 |
| Hispanic ethnicity | 45 | 15.9 | 54 | 18.8 |
| Race | ||||
| Caucasian | 206 | 72.8 | 215 | 74.9 |
| African American | 29 | 10.2 | 28 | 9.8 |
| Other | 48 | 17.0 | 44 | 15.3 |
| Education | ||||
| Less than high school | 63 | 22.3 | 69 | 24.0 |
| High school or GED | 94 | 33.2 | 96 | 33.4 |
| Greater than high school | 126 | 44.5 | 122 | 42.5 |
| Not employed | 179 | 63.3 | 181 | 63.1 |
| Opioid use | ||||
| Primary opioid | ||||
| Opioid analgesics | 43 | 15.8 | 47 | 16.8 |
| Heroin | 230 | 84.2 | 233 | 83.2 |
| Any current heroin use | 248 | 87.6 | 251 | 87.5 |
| Any current intravenous use | 189 | 66.8 | 196 | 68.3 |
| Current methadone prescriptionb | 42 | 14.8 | 52 | 18.1 |
| Mean | SD | Mean | SD | |
|
| ||||
| Primary opioid cost (dollars per day) | 90.7 | 76.7 | 96.3 | 74.5 |
| N | % | N | % | |
|
| ||||
| Other current substance use | ||||
| Cigarette smoker | 250 | 88.3 | 263 | 91.6 |
| Amphetamines | 56 | 19.8 | 72 | 25.1 |
| Cocaine/crack | 112 | 39.6 | 128 | 44.6 |
| Cannabis | 153 | 54.1 | 152 | 53.0 |
| Hallucinogens | 8 | 2.8 | 12 | 4.2 |
| DSM-5 substance use disorder | ||||
| Alcohol | 71 | 25.1 | 88 | 30.7 |
| Amphetamines | 42 | 14.8 | 64 | 22.3 |
| Benzodiazepine/other sedative | 69 | 24.4 | 84 | 29.3 |
| Cannabis | 72 | 25.4 | 91 | 31.7 |
| Cocaine | 75 | 26.5 | 100 | 34.8 |
| Mean | SD | Mean | SD | |
|
| ||||
| History of substance use | ||||
| Age at onset of nicotine use (years) | 15.9 | 5.3 | 15.7 | 4.9 |
| Age at onset of any opioid use (years) | 21.2 | 6.5 | 21.5 | 7.6 |
| Age at onset of heroin use (years) | 25.0 | 7.0 | 24.3 | 7.9 |
| Duration of opioid use (years) | 12.8 | 8.9 | 12.2 | 9.1 |
| N | % | N | % | |
|
| ||||
| Past treatment history | ||||
| Current treatment is first treatment in lifetime | 100 | 35.3 | 109 | 38.0 |
| Any past treatment was successfulc | 123 | 43.5 | 101 | 35.2 |
| Past methadone or buprenorphine treatment was successfulc | 115 | 40.6 | 86 | 30.0 |
| Past naltrexone treatment was successful | 13 | 4.6 | 11 | 3.8 |
| Mean | SD | Mean | SD | |
|
| ||||
| Other psychiatric symptoms or disorders | ||||
| Hamilton Depression Rating Scale score | 8.6 | 6.5 | 9.3 | 6.6 |
| ASI psychiatric domain composite score | 0.3 | 0.2 | 0.3 | 0.6 |
| Anxiety or depression, moderate or extreme (EuroQoL) | 191 | 67.5 | 200 | 69.7 |
| Any psychiatric disorderd | 190 | 67.1 | 191 | 66.6 |
| Pain | ||||
| Chronic pain longer than 6 monthse | 29 | 10.3 | 44 | 15.3 |
| Pain discomfort, moderate or extreme (EuroQoL) | 163 | 57.6 | 172 | 59.9 |
| Criminal justice status: current probation or parole | 42 | 14.9 | 50 | 17.4 |
| Living situation | ||||
| Current homelessnessf | 74 | 26.1 | 69 | 24.0 |
| Any friends or family with alcohol use problems | 131 | 46.8 | 155 | 54.4 |
| Any friends or family with heroin or other opioid use problems | 175 | 62.5 | 171 | 60.0 |
| Any friends or family with illicit drug problems | 173 | 61.8 | 200 | 70.2 |
| Living with a person with alcohol use disorder | 31 | 11.0 | 34 | 11.8 |
| Living with a person using illicit drugs | 59 | 20.8 | 57 | 19.9 |
| Medication preferenceg | ||||
| No strong medication preference | ||||
| Disagree | 85 | 30.1 | 85 | 29.6 |
| Neutral | 110 | 39.0 | 102 | 35.5 |
| Agree | 87 | 30.9 | 100 | 34.8 |
| Prefer to receive buprenorphine-naloxone | ||||
| Disagree | 68 | 24.1 | 73 | 25.4 |
| Neutral | 117 | 41.5 | 122 | 42.5 |
| Agree | 97 | 34.4 | 92 | 32.1 |
| Prefer to receive extended-release naltrexone | ||||
| Disagree | 67 | 23.8 | 62 | 21.6 |
| Neutral | 137 | 48.6 | 136 | 47.4 |
| Agree | 78 | 27.7 | 89 | 31.0 |
| Opioid withdrawal: typical discomfort level during past episodes of opioid withdrawal | ||||
| 0–7 (0=none; 1=little discomfort) | 152 | 53.9 | 148 | 51.7 |
| 8–10 (10=almost unbearable) | 130 | 46.1 | 138 | 48.3 |
| Mean | SD | Mean | SD | |
|
| ||||
| Subjective Opioid Withdrawal Scale (score range, 0–64) | 15.6 | 13.4 | 15.6 | 13.2 |
| N | % | N | % | |
|
| ||||
| Timing of randomization | ||||
| Early (within 3 days of last opioid exposure) | 107 | 37.8 | 110 | 38.3 |
| Late (>3 days since last opioid exposure) | 176 | 62.2 | 177 | 61.7 |
| Severity of opioid use | ||||
| Low (nonintravenous use or intravenous use at <6 bags/day) | 171 | 60.4 | 172 | 59.9 |
| High (intravenous use at ≥6 bags/day) | 112 | 39.6 | 115 | 40.1 |
ASI=Addiction Severity Index; EuroQol=Euro Quality of Life Scale.
Among patients on methadone, only those with prescriptions for <30 mg/day were eligible for the trial.
Patients were asked whether they considered past treatments to be successful (yes or no).
Psychiatric disorders were assessed by clinical history by the medical clinician and included anxiety or panic, attention deficit hyperactivity disorder, bipolar disorder, major depressive disorder, schizophrenia, suicidal ideation, suicidal behavior, psychotic episodes, or other psychiatric disorder.
Chronic pain was assessed by clinical history by the medical clinician.
Homelessness was assessed as an affirmative response to the question “Are you currently homeless or living in a shelter?”
Patients were asked to respond to the following statements: “I do not have a strong preference for which medication I receive”; “I prefer to receive buprenorphine-naloxone”; and “I prefer to receive extended-release naltrexone.”