Stimulant use trajectories and the longitudinal risk of heavy drinking: findings from a rural population-based study

Change in alcohol and other drug use during five years of continuous opioid substitution treatment

BACKGROUND

English national prospective, observational cohort study of patients continuously enrolled for five years in opioid substitution treatment (OST) with oral methadone and sublingual buprenorphine. This is a secondary outcome analysis of change in use of alcohol and other drug use (AOD) following identification of heroin use trajectories during OST.

METHODS

All adults admitted to community OST in 2008/09 and enrolled to 2013/14 (n = 7717). Data from 11 sequential, six-monthly clinical reviews were used to identify heroin and AOD use trajectories by multi-level Latent Class Growth Analysis. OST outcome in the sixth and seventh year was 'successful completion and no re-presentation' (SCNR) to structured treatment and was assessed using multi-level logistic regression.

RESULTS

With 'rapid decreasing' heroin use trajectory as referent, 'continued high-level' heroin use predicted 'continued high-level' crack cocaine use (relative risk ratio [RRR] 58.7; 95% confidence interval [CI] 34.2-100.5),'continued high-level' alcohol use (RRR 1.2; 95% CI 1.0-1.5), 'increasing' unspecified drug use (RRR 1.7; 95% CI 1.4-2.1) and less 'high and increasing' cannabis use (RRR 0.5; 95% CI 0.4-0.6). 'Increasing' crack use was negatively associated with SCNR outcome for the 'decreasing then increasing' and 'gradual decreasing' heroin use groups (adjusted odds ratio [AOR] 0.5; 95% CI 0.3-0.9 and AOR 0.2; 95% CI 0.1-0.7, respectively).

CONCLUSIONS

Continued high-level heroin use non-response during long-term OST is associated with high-level crack cocaine and alcohol use, increasing unspecified drug use, but less high and increasing cannabis use. Increasing use of crack cocaine is negatively associated with the likelihood that long-term OST is completed successfully.

Continuous opioid substitution treatment over five years: Heroin use trajectories and outcomes

BACKGROUND

This is the first national study in England of continuous long-term opioid substitution treatment (OST).

METHODS

All adults were admitted to community OST for opioid use disorder (OUD) in 2008/09 with continuous enrolment to 2013/14 (n = 7719). Heroin use trajectories were identified by multilevel Latent Class Growth Analysis. In Year 6 and 7 of follow-up, the outcome measure (analysed by multilevel, multivariable logistic regression) was 'successful completion and no re-presentation' (SCNR) to community treatment within six months.

RESULTS

Five heroin use trajectory classes were identified: 'gradual decreasing' (20.9%), 'decreasing then increasing' (21.7%), 'continued low-level' (17.0%), 'rapid decreasing' (25.6%), and 'continued high-level' (14.8%). At the end of Year 7, 4616 people (60.3%) remained in OST. Of those discharged, 28.8% achieved the SCNR follow-up outcome. SCNR was more likely in the 'gradual decreasing' (adjusted odds ratio [AOR] 2.40; 95% confidence interval [CI] 1.77-3.26), 'continued low-level' (AOR 2.46; CI 1.78-3.40), and 'rapid decreasing' (AOR 3.40; CI 2.43-4.37) classes relative to the 'continued high-level' class. SCNR was more likely among patients employed at admission (AOR 1.45; 95% CI 1.15-1.83) and those receiving adjunctive psychosocial interventions (AOR 1.44; 95% CI 1.03 to 2.02).

CONCLUSIONS

Among English patients in OST for 5 years, heroin use trajectories were clearly delineated with a gradient of response on the study outcome. Successful completion and no re-presentation was achieved by 28.8% of discharged patients. The rapid decreasing trajectory had the greatest likelihood of positive outcome. Adjunctive psychosocial intervention during OST was associated with positive outcome.

Effectiveness of treatment for opioid use disorder: A national, five-year, prospective, observational study in England

BACKGROUND

This the first 5-year effectiveness study of publicly funded treatment for opioid use disorder (OUD) in England.

METHODS

All adults initiating treatment in 2008/09 in all 149 local treatment systems reporting to the National Drug Treatment Monitoring System (n=54,347). Admission polydrug use sub-populations were identified by Latent Class Analysis. The treatment outcome measure was 'successful completion and no re-presentation within six months' (SCNR) analysed by multilevel, multivariable logistic regression and funnel plots to contrast outcome by treatment system.

RESULTS

SCNR was achieved by 21.9%. Heroin and crack cocaine users were significantly less likely to achieve this outcome than patients who used heroin only (adjusted odds ratio [AOR] 0.90; 95% confidence interval [CI] 0.85-0.95). Older patients (AOR 1.09; CI 1.07-1.11), those employed (AOR 1.27; CI 1.18-1.37) and those enrolled for longer treatment were more likely to achieve the outcome measure. After risk adjustment, the local treatment systems that achieved substantially better outcome performance (14/149) had a lower rate of opiate prevalence in the local population at time of study initiation (incidence rate difference [IRD] 4.1; CI 4.0-4.2), fewer criminal offences per thousand (IRD 28.5; CI 28.1-28.8) and lower drug-related deaths per million (IRD 5.9; CI 5.9-5.9).

CONCLUSIONS

In an English national study, one fifth of patients successful completed treatment for OUD and did not present for further treatment within six months. Longer time in treatment increases the probability of achieving and maintaining clinical benefit from treatment. After risk-adjustment, an important minority of treatment systems achieve substantially better outcome performance.

Post-treatment drinking among HIV patients: Relationship to pre-treatment marijuana and cocaine use

BACKGROUND

For individuals with HIV, heavy drinking can pose serious threats to health. Some interventions are effective at reducing drinking in this population, but many HIV-infected heavy drinkers also use marijuana or cocaine. Although these drugs have predicted poor alcohol outcomes in other treatment studies, whether this occurs among HIV patients who drink heavily is unknown.

METHODS

Participants were binge-drinking HIV primary care patients (N=254) enrolled in a randomized trial of three brief drinking interventions over 60 days that varied in intensity. We investigated the relationship of baseline past-year drug use (marijuana-only, cocaine-only, both, neither) to end-of-treatment drinking quantity and frequency. We also evaluated whether the relationship between intervention type and end-of-treatment drinking varied by baseline drug use. Final models incorporated control for patients' demographic and HIV characteristics.

RESULTS

In final models, drinking frequency at the end of treatment did not vary by baseline drug use, but drinking quantity did (X(2)[3] = 13.87, p < 0.01), with individuals using cocaine-only drinking significantly more per occasion (B = 0.32, p < 0.01). Baseline drug use also interacted with intervention condition in predicting end-of-treatment drinking quantity (X(2)[6] = 13.98, p < 0.05), but not frequency, with the largest discrepancies in end-of-treatment drinks per drinking day by intervention intensity among cocaine-only patients.

CONCLUSIONS

In general, HIV patients using cocaine evidenced the highest levels of drinking after alcohol intervention. However, these individuals also evidenced the most pronounced differences in end-of-treatment drinking by intervention intensity. These results suggest the importance of more intensive intervention for individuals using alcohol and cocaine.

Predictors of alcohol use among rural drug users after disclosure of hepatitis C virus status

OBJECTIVE

Alcohol consumption dramatically increases the risk of liver damage among those with hepatitis C virus (HCV) infection, yet the impact of HCV status disclosure and standard informational counseling on alcohol use among rural drug users remains poorly understood.

METHOD

In this prospective study, 503 rural Appalachian drug users were recruited using respondent-driven sampling. Participants were tested for HCV antibodies, and data on sociodemographic characteristics, lifetime and past-30-day drug and alcohol use, and psychiatric disorders were collected by interviewer-administered questionnaires. A total of 470 participants returned after 6 months for follow-up; however,4 of those had no history of alcohol use, thus leaving a final sample size of 466. Multivariate negative binomial regression was used to determine the effect of disclosure of HCV status and posttest counseling on alcohol consumption at follow-up.

RESULTS

Despite an overall decrease in drinking frequency in the cohort, those who were HCV-positive were drinking at a frequency similar to their HCV-negative counterparts at follow-up, despite posttest counseling informing them of the risks of alcohol use with an HCV diagnosis (adjusted incidence rate ratio = 1.07, 95% CI [0.72, 1.61]). Significant predictors of increased days of alcohol use after 6 months included baseline alcohol use, baseline marijuana use, and meeting the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for antisocial personality disorder. Those using OxyContin at baseline had significantly fewer days of alcohol use at follow-up.

CONCLUSIONS

HCV status disclosure and standard informational counseling alone do not curtail drinking among HCV-positive drug users in the rural setting. Targeted interventions with regard to alcohol use are warranted in order to mitigate the damage of the HCV epidemic.

Stimulant use, religiosity, and the odds of developing or maintaining an alcohol use disorder over time

OBJECTIVE

Little is known about whether cocaine or methamphetamine use, particularly among stimulant users residing in rural areas, is associated with increased odds of developing or maintaining an alcohol use disorder (AUD) over time. One factor that may help to protect some users against the development of an AUD is religiosity. This study examined how stimulant use and religiosity are associated longitudinally with the odds of an AUD among a rural population-based cohort of stimulant users.

METHOD

Recent stimulant users (N = 710) were recruited via respondent-driven sampling and were interviewed every 6 months over a 3-year period. Concurrent and lagged generalized estimating equations analyses were conducted to estimate how past-30- day crack cocaine, powder cocaine, and methamphetamine use; religiosity; and other covariates were associated with the odds of an AUD.

RESULTS

At baseline, 56% of the participants met AUD criteria. The odds of an AUD declined significantly over time in the concurrent, but not the lagged, model. Crack cocaine use was associated with increased odds of an AUD in both models, although the strength of the concurrent association between an AUD and crack cocaine use declined over time. Powder cocaine use and more frequent church attendance also were concurrently associated with decreased odds of an AUD.

CONCLUSIONS

Rural stimulant users, especially those using cocaine, could potentially benefit from treatment for both alcohol use and stimulant use. In addition, our findings suggest that greater frequency of church attendance may be related to lower odds of the development or maintenance of an AUD.