Effects of injectable extended-release naltrexone (XR-NTX) for opioid dependence on residential rehabilitation outcomes and early follow-up.

BACKGROUND AND OBJECTIVES: Little is known about the use of extended-release naltrexone (XR-NTX) during residential rehabilitation, and its effects on early outcomes and rates of follow-up treatment. This study examined patient characteristics and rates of treatment completion and engagement in post-residential care of opioid dependent patients who received XR-NTX during residential rehabilitation, compared with patients who did not receive this medication. METHODS: Electronic records for opioid dependent patients from three Pennsylvania residential detoxification and treatment facilities (N = 7,687) were retrospectively analyzed. We determined the proportion of patients who received XR-NTX (INJ), and compared rates of treatment completion and engagement in follow-up care relative to a naturalistic control group of patients recommended for, but not administered, XR-NTX (Non-INJ). Data on whether the patient initiated follow-up care were available from one site (N = 3,724). RESULTS: Overall, 598 (7.8%) patients were recommended for XR-NTX and of these, 168 (28.1%) received injections. Compared to non-INJ patients, INJ patients were less likely to leave against medical advice (4.8% vs. 30.2%, p < .001) and more likely to initiate follow-up care (37.7% vs. 19.7%, p < .001). These differences remained significant after controlling for demographic covariates using regression analysis. CONCLUSIONS: XR-NTX was associated with higher rates of residential and early post-residential care engagement in patients with opioid dependence. SCIENTIFIC SIGNIFICANCE: XR-NTX may be an effective adjunct in the residential treatment and aftercare of patients with opioid dependence.

Injectable extended-release naltrexone for opioid dependence: a double-blind, placebo-controlled, multicentre randomised trial.

BACKGROUND: Opioid dependence is associated with low rates of treatment-seeking, poor adherence to treatment, frequent relapse, and major societal consequences. We aimed to assess the efficacy, safety, and patient-reported outcomes of an injectable, once monthly extended-release formulation of the opioid antagonist naltrexone (XR-NTX) for treatment of patients with opioid dependence after detoxification. METHODS: We did a double-blind, placebo-controlled, randomised, 24-week trial of patients with opioid dependence disorder. Patients aged 18 years or over who had 30 days or less of inpatient detoxification and 7 days or more off all opioids were enrolled at 13 clinical sites in Russia. We randomly assigned patients (1:1) to either 380 mg XR-NTX or placebo by an interactive voice response system, stratified by site and gender in a centralised, permuted-block method. Participants also received 12 biweekly counselling sessions. Participants, investigators, staff , and the sponsor were masked to treatment allocation. The primary endpoint was the response profile for confirmed abstinence during weeks 5­24, assessed by urine drug tests and self report of non-use. Secondary endpoints were self-reported opioid-free days, opioid craving scores, number of days of retention, and relapse to physiological opioid dependence. Analyses were by intention to treat. This trial is registered at ClinicalTrials.gov, NCT00678418. FINDINGS: Between July 3, 2008, and Oct 5, 2009, 250 patients were randomly assigned to XR-NTX (n=126) or placebo (n=124). The median proportion of weeks of confirmed abstinence was 90·0% (95% CI 69·9­92·4) in the XR-NTX group compared with 35·0% (11·4­63·8) in the placebo group (p=0·0002). Patients in the XR-NTX group self-reported a median of 99·2% (range 89·1­99·4) opioid-free days compared with 60·4% (46·2­94·0) for the placebo group (p=0·0004). The mean change in craving was ­10·1 (95% CI ­12·3 to ­7·8) in the XR-NTX group compared with 0·7 (­3·1 to 4·4) in the placebo group (p<0·0001). Median retention was over 168 days in the XR-NTX group compared with 96 days (95% CI 63­165) in the placebo group (p=0·0042). Naloxone challenge confirmed relapse to physiological opioid dependence in 17 patients in the placebo group compared with one in the XR-NTX group (p<0·0001). XR-NTX was well tolerated. Two patients in each group discontinued owing to adverse events. No XR-NTX-treated patients died, overdosed, or discontinued owing to severe adverse events. INTERPRETATION: XR-NTX represents a new treatment option that is distinct from opioid agonist maintenance treatment. XR-NTX in conjunction with psychosocial treatment might improve acceptance of opioid dependence pharmacotherapy and provide a useful treatment option for many patients. FUNDING: Alkermes.

Thirty Years of TheASAMCriteria: A Report Card.

The American Society of Addiction Medicine Criteria (ASAM) Criteria has profoundly influenced addiction treatment and reimbursement, with its growing toolkit of ASAM CONTINUUM software, ASAM-CARF Level of Care Certification Program, educational programs, and publications. A retrospective accounting shows that the field has made considerable strides, but has far to go. Providers and payers still need to (1) improve consistency in their use of standardized, multidimensional patient assessment; (2) improve flexibility in providing and reimbursing person-centered, individualized services; (3) improve measurement in treatment planning for determination of progress; and (4) focus on outcomes and value in the care they deliver.

Practical Technology for Expanding and Improving Substance Use Disorder Treatment: Telehealth, Remote Monitoring, and Digital Health Interventions.

The US opioid crisis and the COVID-19 pandemic have sparked innovation in substance use disorder (SUD) treatment such that telehealth, remote monitoring, and digital health interventions are increasingly feasible and effective. These technologies can increase SUD treatment access and acceptability, even for nontreatment seeking, remote, and underserved populations, and can be used to reduce health disparities. Overall, digital tools will likely overcome many barriers to delivery of evidence-based behavioral treatments such as cognitive behavioral therapy and contingency management, that, along with appropriate medications, constitute the foundation of treatment of SUDs.

Efficacy of extended-release naltrexone in patients with relatively higher severity of alcohol dependence.

BACKGROUND: Because some literature reviews have suggested that naltrexone's benefit may be limited to less-severe alcohol dependence, and exclusively to reduction in heavy drinking rather than abstinence, we examined the efficacy of once per month, injectable extended-release naltrexone (XR-NTX 380 mg) in patients with relatively higher severity alcohol dependence. METHODS: Post hoc analyses examined data from a multicenter, placebo-controlled, 24-week randomized trial of XR-NTX for alcohol dependence (N = 624). We analyzed treatment effects in alcohol-dependent patients who had higher baseline severity, as measured by: (i) the Alcohol Dependence Scale (ADS) or (ii) having been medically detoxified in the week before randomization. Efficacy was also examined via the relationship between pretreatment severity indices and reporting at least 4 days of lead-in abstinence prior to treatment-a major predictor of good outcome in the original study. RESULTS: Higher severity alcohol-dependent patients, defined by the ADS, when receiving XR-NTX 380 mg (n = 50) compared with placebo (n = 47), had significantly fewer heavy-drinking days in-trial (hazard ratio=0.583; p = 0.0049) and showed an average reduction of 37.3% in heavy-drinking days compared with 27.4% for placebo-treated patients (p = 0.039). Among those who had a detoxification just prior to randomization, these reductions were 48.9% (XR-NTX 380 mg; n = 11) and 30.9% (placebo; n = 15) (p = 0.004). Subjects with at least 4 days of pretreatment abstinence (n = 82) versus those without (n = 542) had significantly higher pretreatment ADS scores (p = 0.002) and were more likely to require detoxification prior to randomization (p < 0.001). Patients with lead-in abstinence experienced significantly better maintenance of initial and 6-month abstinence. CONCLUSIONS: These secondary analyses support the efficacy of XR-NTX 380 mg in relatively higher severity alcohol dependence for both reduction in heavy drinking and maintenance of abstinence, with implications for the role of adherence pharmacotherapy.

Long-term opioid blockade and hedonic response: preliminary data from two open-label extension studies with extended-release naltrexone.

The emergence of extended-release naltrexone (XR-NTX) raises the opportunity to explore the role of endorphin blockade on hedonic response during long-term alcohol dependence treatment. A hedonic survey was administered to 74 alcohol dependent patients treated for an average of 3.5 years with nearly continuous month-long intramuscular XR-NTX. The paper-and-pencil, one-time survey asked patients about the degree of pleasure they experienced in the past 90 days with drinking alcohol, sex, exercise and other daily activities. The data revealed lower pleasure ratings for alcohol than for sex, exercise and 10 other common activities. Mean responses to drinking alcohol and gambling were significantly lower than to listening to music, sex, reading, being with friends, eating good food, eating spicy food, and playing video/card games. This effect was independent of XR-NTX dose or duration. Although this exploratory study lacked baseline data, a comparison group or control for the impact of patient discontinuation, the data indicate the feasibility of examining long-term hedonic response in recovery. The differential hedonic ratings suggest that, in patients who persist with long-term continuous therapy, XR-NTX may selectively inhibit the pleasure associated with drinking alcohol, compared to a variety of other activities.

Effects of naltrexone treatment for alcohol-related disorders on healthcare costs in an insured population.

OBJECTIVE: To determine the impact of treatment with oral naltrexone on healthcare costs in patients with alcohol-related disorders. METHODS: Using data from the MarketScan Commercial Claims and Encounters Database for 2000-2004, we identified a naltrexone group (with an alcohol-related diagnosis and at least one pharmacy claim for oral naltrexone) and two control groups. Alcohol controls had an alcohol-related diagnosis and were not prescribed an alcoholism treatment medication. Nonalcohol controls had no alcohol-related diagnosis and no prescription for an alcoholism treatment medication. The control groups were matched three to one to the naltrexone group on demographic and other relevant measures. Healthcare expenditures were calculated for the 6-month periods before and after the index naltrexone drug claim (or matched date for controls). Univariate and multivariate analyses were used to compare the groups on key characteristics and on healthcare costs. RESULTS: Naltrexone patients (n = 1,138; 62% men; mean age 45 +/- 11 years) had significantly higher total healthcare expenditures in the pre-index period than either of the control groups. In the postindex period, naltrexone patients had a significantly smaller increase than alcohol controls in total alcohol-related expenditures. Total nonalcohol-related expenditures also increased significantly less for the naltrexone group than for the alcohol control group. Multivariate analyses showed that naltrexone treatment significantly reduced alcohol-related, nonalcohol-related, and total healthcare costs relative to alcohol controls. CONCLUSIONS: Although prior to treatment patients with alcohol-related disorders had higher healthcare costs, treatment with oral naltrexone was associated with reductions both in alcohol-related and nonalcohol-related healthcare costs.

Effect of extended-release naltrexone (XR-NTX) on quality of life in alcohol-dependent patients.

BACKGROUND: Extended-release naltrexone (XR-NTX) is a once-a-month injectable formulation for the treatment of alcohol dependence previously shown to reduce drinking and heavy drinking relative to placebo (Garbutt et al., 2005). A 24-week, randomized, double-blind, placebo-controlled study established the efficacy and safety of XR-NTX in this patient population. In this report, the effect of XR-NTX on quality of life (QOL) was examined. METHODS: Alcohol-dependent patients were randomly assigned to receive XR-NTX 380 mg (N = 205), XR-NTX 190 mg (N = 210), or placebo (N = 209), combined with a standardized psychosocial intervention. QOL was assessed using the Medical Outcomes Study 36-item short-form health survey, administered at baseline and at 4-week intervals during 24 weeks of treatment. RESULTS: Compared with U.S. population norms, patients showed initial impairment in the health-related QOL domains of mental health, social functioning, and problems with work or other daily activities due to emotional problems. Adherence to all 6 injections was 65% for XR-NTX 190 mg, 63% for XR-NTX 380 mg, and 64% for placebo. Generalized estimating equations analyses using an intention-to-treat sample revealed that XR-NTX 380 mg was associated with significantly greater improvements from baseline in mental health (p = 0.0496), social functioning (p = 0.010), general health (p = 0.048), and physical functioning (p = 0.028), compared with placebo. Linear regression analyses revealed that reductions from baseline in drinking (percentage of drinking days and percentage of heavy drinking days in the last 30 days) were significantly (p < 0.05) correlated with improvements in quality of life. CONCLUSION: Extended-release naltrexone 380 mg in combination with psychosocial intervention was associated with improvements in QOL, specifically in the domains of mental health, social functioning, general health, and physical functioning.

Decreased absolute amygdala volume in cocaine addicts.

The amygdala is instrumental to a set of brain processes that lead to cocaine consumption, including those that mediate reward and drug craving. This study examined the volumes of the amygdala and hippocampus in cocaine-addicted subjects and matched healthy controls and determined that the amygdala but not the hippocampus was significantly reduced in volume. The right-left amygdala asymmetry in control subjects was absent in the cocaine addicts. Topological analysis of amygdala isosurfaces (population averages) revealed that the isosurface of the cocaine-dependent group undercut the anterior and superior surfaces of the control group, implicating a difference in the corticomedial and basolateral nuclei. In cocaine addicts, amygdala volume did not correlate with any measure of cocaine use. The amygdala symmetry coefficient did correlate with baseline but not cocaine-primed craving. These findings argue for a condition that predisposes the individual to cocaine dependence by affecting the amygdala, or a primary event early in the course of cocaine use.

Overriding the blockade of antinociceptive actions of opioids in rats treated with extended-release naltrexone.

A monthly extended-release formulation of the opioid antagonist naltrexone (XR-NTX) is approved for treatment of alcohol dependence. There is little research regarding overriding chronic (>21 days) competitive opioid receptor blockade with opioids for acute pain. Using the hot plate test after XR-NTX or placebo microsphere administration, rats were treated with an opioid analgesic to determine the dose required to produce the maximum response latency (MRL; 60 s). Rats were later treated with the same opioid to determine any potential effects on respiration rate or locomotor activity. In naïve rats, 15 mg/kg morphine, 0.1 mg/kg fentanyl and 8 mg/kg hydrocodone produced MRL. In XR-NTX treated rats, morphine produced 36% and 46% MRL at 90 mg/kg on days 4 and 19 and 96% MRL at 45 mg/kg on day 39. Fentanyl produced 100% MRL at 2.0 mg/kg on days 4 and 19 and at 0.5 mg/kg on day 39. Hydrocodone (80 mg/kg) produced 69%, 80% and 100% MRL on days 4, 19 and 39. Compared to placebo, these doses did not further depress respiration or alter locomotor activity. Thus, opioid receptor blockade with XR-NTX can be overcome in rats with higher doses of opioids without further affecting respiration or locomotor activity.

Reduction in heavy drinking as a treatment outcome in alcohol dependence.

In the field of clinical alcohol disorders treatment in North America, abstinence continues to be largely viewed as the optimal treatment goal; however, there is a growing awareness of limitations when abstinence is considered the only successful outcome. Although this issue has been discussed in research settings, new studies on the public health significance of heavy drinking (defined as five or more standard drinks per drinking day in men, and four or more standard drinks per drinking day in women) in the past 10 years suggest that clinical providers should consider the value of alternative outcomes besides abstinence. A focus on abstinence as the primary outcome fails to capture the impact of treatment on reduction in the pattern and in the frequency of alcohol consumption. In addition, evaluating reduction in drinking as "positive" has value for patients as an indicator of clinical progress. Measurement of continuous variables, such as the quantity and the frequency of alcohol consumption, has provided a clearer understanding of the scope of alcohol-related morbidity and mortality at the societal level, and of the relationship between individual patient characteristics and the naturalistic course of alcohol use, abuse, and dependence. A review of these characteristics suggests that there are clinical benefits associated with reducing heavy drinking in alcohol-dependent patients. Given the significant public health consequences associated with heavy drinking and the benefits associated with its reduction, it is proposed that researchers, public health professionals, and clinicians consider using reduction in heavy drinking as a meaningful clinical indicator of treatment response, and that outcomes be individualized to patients' goals and readiness to change.

Open-label Study of Injectable Extended-release Naltrexone (XR-NTX) in Healthcare Professionals With Opioid Dependence.

OBJECTIVES: Healthcare professionals (HCPs) with opioid dependence are at risk for relapse and death, particularly in the first year of recovery; however, maintenance treatment with opioid agonists is controversial in this safety-sensitive group. We evaluated long-term safety, tolerability, and treatment outcomes of injectable, intramuscular, extended-release naltrexone (XR-NTX) in opioid-dependent HCPs. METHODS: This single-arm, multisite, open-label study was conducted in opioid-dependent HCPs who had been detoxified from opioids for at least 2 weeks. Subjects received monthly XR-NTX injections for up to 24 months, combined with counseling via intensive outpatient substance abuse treatment programs. Assessments included monthly urine opioid drug tests and routine safety assessments, along with a trimonthly short form (36) Health Survey, opioid craving questionnaire, and Treatment Satisfaction Questionnaire for Medication. RESULTS: Of 49 opioid-dependent HCPs screened, 38 enrolled and received at least 1 XR-NTX injection. Most were female (n = 31) and nurses or nursing assistants (n = 30). More than half (n = 21; 55.3%) received at least 12 injections. Seven discontinued due to adverse events (3 anxiety, 2 headache, 1 injection-site mass, 1 derealization). None experienced relapses to opioid dependence necessitating detoxification, overdose, or death during treatment. At 24 months, mean opioid craving fell by 45.2%, and short form (36) mental component scores improved by 31.1% from baseline and approached normal levels. Of 22 unemployed subjects at baseline, 45.5% improved employment status at 24 months. CONCLUSIONS: Long-term (2 years) XR-NTX was associated with no new safety concerns, and, compared with shorter-term studies in the general population, similar or better rates of retention, opioid-negative urines, opioid craving reduction, mental health functional quality of life improvement, and re-employment.

Combined pharmacotherapies and behavioral interventions for alcohol dependence: the COMBINE study: a randomized controlled trial.

CONTEXT: Alcohol dependence treatment may include medications, behavioral therapies, or both. It is unknown how combining these treatments may impact their effectiveness, especially in the context of primary care and other nonspecialty settings. OBJECTIVES: To evaluate the efficacy of medication, behavioral therapies, and their combinations for treatment of alcohol dependence and to evaluate placebo effect on overall outcome. DESIGN, SETTING, AND PARTICIPANTS: Randomized controlled trial conducted January 2001-January 2004 among 1383 recently alcohol-abstinent volunteers (median age, 44 years) from 11 US academic sites with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnoses of primary alcohol dependence. INTERVENTIONS: Eight groups of patients received medical management with 16 weeks of naltrexone (100 mg/d) or acamprosate (3 g/d), both, and/or both placebos, with or without a combined behavioral intervention (CBI). A ninth group received CBI only (no pills). Patients were also evaluated for up to 1 year after treatment. MAIN OUTCOME MEASURES: Percent days abstinent from alcohol and time to first heavy drinking day. RESULTS: All groups showed substantial reduction in drinking. During treatment, patients receiving naltrexone plus medical management (n = 302), CBI plus medical management and placebos (n = 305), or both naltrexone and CBI plus medical management (n = 309) had higher percent days abstinent (80.6, 79.2, and 77.1, respectively) than the 75.1 in those receiving placebos and medical management only (n = 305), a significant naltrexone x behavioral intervention interaction (P = .009). Naltrexone also reduced risk of a heavy drinking day (hazard ratio, 0.72; 97.5% CI, 0.53-0.98; P = .02) over time, most evident in those receiving medical management but not CBI. Acamprosate showed no significant effect on drinking vs placebo, either by itself or with any combination of naltrexone, CBI, or both. During treatment, those receiving CBI without pills or medical management (n = 157) had lower percent days abstinent (66.6) than those receiving placebo plus medical management alone (n = 153) or placebo plus medical management and CBI (n = 156) (73.8 and 79.8, respectively; P<.001). One year after treatment, these between-group effects were similar but no longer significant. CONCLUSIONS: Patients receiving medical management with naltrexone, CBI, or both fared better on drinking outcomes, whereas acamprosate showed no evidence of efficacy, with or without CBI. No combination produced better efficacy than naltrexone or CBI alone in the presence of medical management. Placebo pills and meeting with a health care professional had a positive effect above that of CBI during treatment. Naltrexone with medical management could be delivered in health care settings, thus serving alcohol-dependent patients who might otherwise not receive treatment. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00006206.

A Naturalistic Evaluation of Extended-Release Naltrexone in Clinical Practice in Missouri.

The purpose of this study was to compare the naturalistic outcomes of individuals with alcohol or opioid use problems who were treated with extended-release naltrexone (XR-NTX) to those treated with psychosocial treatment only and also to those treated with other medication-assisted therapies in Missouri during 2010 to 2011. We analyzed intake and discharge data collected as part of SAMHSA's Treatment Episode Data Set assessments. Patients who received XR-NTX during their treatment episode were compared, for those reporting alcohol (but not opioids) as their problem (N=21,137), to those who received oral naltrexone, acamprosate, and psychosocial treatment only, and for those who reported opioids as a problem (N=8996), to those receiving oral naltrexone, buprenorphine/naloxone, and psychosocial treatment only. Group differences were adjusted using propensity score weighting, with propensity scores derived from 18 intake variables. For the alcohol sample, patients who received XR-NTX vs. the oral naltrexone group had superior composite outcomes on a measure combining abstinence, self-help participation, employment, and arrests. For the opioid sample, XR-NTX was found to have significantly better outcomes than oral naltrexone on the composite outcome measure. For both the alcohol and opioid samples, the group that received XR-NTX stayed in treatment longer vs. psychosocial treatment only. In the opioid sample, those receiving buprenorphine/naloxone remained in treatment longer than those receiving XR-NTX.

Prevalence of physical and sexual abuse among substance abuse patients and impact on treatment outcomes.

More than half of substance abusers entering addiction treatment report a history of physical or sexual abuse. It is unclear if such a history impacts treatment outcomes. This one-year follow-up study of 700 substance abusers sought to clarify the relationship between lifetime physical and/or sexual abuse and addiction treatment outcome to help address the specific needs of this population. To achieve this goal, baseline characteristics, no-show for treatment status, post-treatment clinical outcomes, and treatment history were studied for subjects with lifetime history of abuse (47.3%) versus without. Abused subjects, predominantly women, were significantly more impaired at baseline on clinical dimensions including family/social severity and psychiatric severity as measured by the Addiction Severity Index (ASI), and general level of functioning. The two groups endorsed different drugs as primary, with the abused group less frequently endorsing heroin and cocaine in favor of alcohol and polydrug use. Abused subjects reported more prior medical and psychiatric treatments. Abuse history was not a predictor of no-show for treatment. Over the 1-year follow-up, lifetime physical and/or sexual abuse was significantly associated with worse psychiatric status and more psychiatric hospitalizations and outpatient treatment despite receiving similar intensive addiction treatment.

The effect of 12-step self-help group attendance and participation on drug use outcomes among cocaine-dependent patients.

OBJECTIVE: Although cocaine-dependent patients are frequently referred to 12-step self-help groups, little research has examined the benefits of 12-step group attendance in this population. Moreover, the distinction between attending meetings and actively participating in 12-step activities has not typically been examined. METHOD: In the National Institute on Drug Abuse Collaborative Cocaine Treatment Study, 487 cocaine-dependent outpatients were recruited at five sites for a randomized controlled trial of 24-week behavioral treatments. Study data were examined to see whether self-help attendance or active participation were related to subsequent drug use. RESULTS: Twelve-step group attendance did not predict subsequent drug use. However, active 12-step participation in a given month predicted less cocaine use in the next month. Moreover, patients who increased their 12-step participation during the first 3 months of treatment had significantly less cocaine use and lower ASI Drug Use Composite scores in the subsequent 3 months. Finally, Individual Drug Counseling, based on a 12-step model, and increasing levels of 12-step participation each offered discrete benefits. CONCLUSIONS: Results suggest that active 12-step participation by cocaine-dependent patients is more important than meeting attendance, and that a combination of Individual Drug Counseling and active 12-step participation is effective for these patients.

Developing a baseline assessment battery: balancing patient time burden with essential clinical and research monitoring.

OBJECTIVE: Baseline assessment in a multisite alcohol-dependence treatment study has several purposes: addressing inclusion/exclusion criteria and characterizing participants to illuminate subsequent efficacy and safety patterns of the interventions. Combination pharmacotherapy and behavioral therapy trials, however, require more complex assessments than single-modality studies. Medication trials require measures of initial safety for study drug as well as for subsequent side-effect and adverse-effect monitoring (e.g., physical examination, laboratory markers, somatic symptoms, medical conditions and concomitant medications). Behavioral therapy trials (and in some cases medication trials) warrant baseline measurement of mediators of therapy effect (e.g., prior treatment history, motivation for change, self-efficacy, other psychiatric conditions, treatment expectations and network supports). Measures may be needed to interpret interactions that may be discovered between these modalities. METHOD: The National Institute on Alcohol Abuse and Alcoholism COMBINE Study evaluated the potentially overwhelming number of candidate instruments through an iterative process, using the following sequence to finalize a rational baseline assessment battery: key constructs, representative measures, determination of duration of assessment, risk of assessment reactivity, goal priorities, necessity for measure "pruning" and order of measure presentation. After selecting the draft battery, feasibility was evaluated in a pilot study prior to the main trial. RESULTS: The battery was feasible to administer and avoided unintended selection bias. Dropout was substantial, however, and differences across sites in baseline assessment completion rates reflected a tendency of a central intake model to function as an initial filter of dropouts, compared with a direct recruitment model. CONCLUSIONS: This process holds several potentially useful lessons for investigators.

Factorial designs in clinical trials: options for combination treatment studies.

OBJECTIVE: This study reviews the use of factorial designs in clinical trials investigating combinations of therapies. METHOD: Factorial designs may be used when (1) the factors are regarded as being independent or (2) the factors are thought to be complementary and a specific aim is to investigate these interactions. We describe what is meant by a factorial design and the issues that need to be addressed when using such a design. We discuss these issues in general and describe how they have been addressed in various prevention trials and in the COMBINE Study, which is a treatment trial of combinations of therapies for alcohol dependence. RESULTS: Trials of type (1) can provide substantial cost savings in conducting multiple unrelated prevention studies in the same group of participants. Such a factorial trial poses few design challenges beyond those of a standard parallel group trial. Trials of type (2) require consideration of aspects that are intrinsic to the factorial design. CONCLUSIONS: A factorial design is a useful way to examine the effects of combinations of therapies, but it poses challenges that need to be addressed in determining the appropriate sample size and in conducting interim and final statistical analyses.

Design and analysis of trials of combination therapies.

OBJECTIVE: Combination therapies can have significant advantages over monotherapies. Combinations of therapies can provide additive (or even synergistic) effects on efficacy. They may permit use of lower doses of each component to achieve a given level of efficacy, improving tolerability and reducing adverse effects. A multicomponent treatment may facilitate tailoring of therapy to the needs of individual patients (e.g., treatment augmentation in nonresponders). These characteristics seem highly attractive in developing treatment strategies for alcohol abuse and dependence, because existing monotherapies have shown modest efficacy, at best. METHOD: However, trials of combination therapies present challenges in design, execution and interpretation, including: (1) choice of the treatment combinations to be compared; (2) definition of primary and secondary hypotheses; (3) differences between interventions in the duration of treatment, the time lag from the start of treatment to an observable effect on outcomes and interval for assessment of efficacy; (4) study power/sample size; (5) logistics of treatment delivery, masking and outcome assessment; and (6) attribution of adverse events. RESULTS: Most of these issues arose in the COMBINE project, a sequence of trials intended to explore the use of combinations of behavioral and pharmacological approaches in the treatment of alcohol dependence. The resolution and impact of the challenges above for the COMBINE trial will be described. CONCLUSIONS: Trials of combination therapies address many important clinical questions; however, their level of complexity requires considerable forethought, pilot investigations and organization.