Quantity of Research Available

A total of 977 citations were identified in the literature search. Following screening of titles and abstracts, 962 citations were excluded and 15 potentially relevant reports from the electronic search were retrieved for full-text review. One potentially relevant publication was retrieved from the grey literature search. Of these potentially relevant articles, 11 publications were excluded for various reasons, while five publications (one systematic review [SR], three primary clinical studies, one guideline) met the inclusion criteria and were included in this report. Appendix 1 describes the PRISMA flowchart of the study selection.

Summary of Study Characteristics

The included narrative systematic review (SR)⁶ included 22 studies on community detoxification for adult patients with alcohol dependence (AD) and/or alcohol withdrawal. Follow-up periods ranged from one to 12 months. Most included studies did not have a comparator; two studies compared inpatient to outpatient settings. Outcomes included detoxification completion rate (percentage of patients who completed the detoxification program) and effectiveness of the program on abstinence and drinking outcomes, using validated scales. The study was conducted in UK, India and the US.

The included clinical trials were randomized controlled (RCT),⁷ longitudinal observational,⁸ and retrospective observational⁹ studies. The studies compared inpatient to outpatient care in adult patients with alcohol abuse^7,8 or substance use disorders.⁹ Primary outcomes included abstinence (using self-reported questionnaires, confirmed by blood chemistry),⁷ number of drinks per drinking day,⁷ the amount of alcohol consumed in 12 months after treatment entry,⁸ and treatment completion rate.⁹The studies were conducted in the US.

The included guideline is a British Columbia Ministry of Health evidence based guideline for the clinical management of adults with opioid use disorder.¹⁰ Guideline content and recommendations were based on a structured review of the literature (details not reported). The evidence and recommendation rating were adopted from the classification developed by the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) workgroup. Characteristics of the included studies are detailed in Appendix 2.

Summary of Critical Appraisal

The included SR⁶ had an a priori design provided, independent study selection and data extraction procedure in place, performed by two reviewers, a comprehensive literature search was performed, a list of included studies and study characteristics were provided, and conflicts of interest were stated for the authors of the review. The study did not perform meta-analysis due to heterogeneity in patient eligibility and reporting outcomes among the included studies, did not assess publication bias (rationale not provided) or quality of the included studies, which would caution the interpretation of the review conclusions; and a list of excluded studies was not provided.

The included studies^7-9had clearly described hypotheses, method of selection from source population and representation of the study population (i.e., patients with high alcohol involvement), main outcomes, interventions, patient characteristics, and main findings. Estimates of random variability and actual probability values were provided. The RCT⁷ included only patients with high alcohol involvement limiting the generalizability of the findings to patients with lower alcohol involvement. Randomization was done effectively and the research staff was blinded to participants’ setting assignment. The longitudinal observational study had baseline patients characteristics that were clinically and statistically different in the two groups (such as age, alcohol consumption and symptoms at intake), leading to cautioned interpretation of the findings, and it is uncertain to have enough power to detect clinically important effects between groups (power calculation not performed).⁸ The retrospective observational study had variable criteria and definitions of the main outcomes (e.g., for “successful completion”) across programs.⁹

The included guideline¹⁰ had a clear scope and purpose, the recommendations are specific and unambiguous, methods used for formulating the recommendations were clearly described, health benefits, side effects and risks were stated in the recommendations, and the procedures for updating the guidelines provided and target users of the guideline are clearly defined. The methods for searching for and selecting the evidence were unclear. Potential cost implications of applying the recommendation were not included. It was unclear whether the guideline was piloted among target users, or whether patients’ views and preferences were sought.

Details of the critical appraisal of the included studies are presented in Appendix 3.

Summary of Findings

1.

What is the clinical effectiveness of inpatient and outpatient treatment programs in adults with sub stance use disorders?

The narrative review reported the effectiveness and safety of community detoxification on adults with alcohol dependence.⁶ Comparative outcomes between outpatient care (community) and inpatient care were reported in two studies with short follow-up periods (one or two months). A better detoxification completion rate with outpatient care than inpatient care was found in one quasi-experimental study and one RCT. Outpatient care also led to better abstinence rates in one RCT and drinking outcomes in one quasi-experimental study. Drinking outcomes were not further specified but were categorized as “good”, “improved”, “unimproved”, or “unknown”; the difference between “good” and “improved” was not reported. Statistical significance was not reported for any comparison. There were no differences found in safety outcomes such as visual hallucination, suicidality and seizure between the two treatments. The authors concluded that evidence supports the case for community detoxification in patients with alcohol dependence.

The RCT with longer term follow-up (up to 18 months ) reported the comparative effectiveness of community detoxification and inpatient care on adults with high-severity alcohol use disorder.⁷ It found a statistically significant advantage for inpatient treatment (followed by 6 months outpatient care) in the percentage of days abstinent (PDA) over outpatient care (plus an additional 6 months outpatient care) in the first month post-treatment, but the advantage was reduced by month 6 when the difference was no longer significant. A considerable agreement was observed between self-reported outcomes and blood chemistry assessments (the odds of a negative blood index doubled with each 10% increase in PDA). Monthly point prevalence abstinence (PPA) (probability of complete abstinence per month) was also in favour of inpatient care at month 1 and at month 6. Inpatients experienced drinking reduction, as measured by number of drinks per drinking day, while outpatients did not. Large drinking reduction was observed among participants with low-severity alcohol use in both inpatient and outpatient care, while large drinking reduction was observed among high-severity alcohol use participants in inpatient care only. The authors concluded that the evidence found initial but decreasing benefit of inpatient over outpatient care across time.

The prospective study reported the comparative effectiveness of inpatient and outpatient care (patients lived at home and commuted to the hospital to attend treatment) on adults with alcohol use disorders.⁸ The study found inpatients consumed significantly less alcohol in the year after entering treatment than outpatients as measured by the Graduated Frequency Scale questionnaire, and had significantly greater engagement with Alcohol Anonymous program than outpatients in the year after treatment. It is noteworthy that self-reporting measures for alcohol consumption are subjective.

The retrospective study reported the comparative effectiveness of inpatient and outpatient care (details not specified) on adults with substance use disorders (alcohol, cocaine, marijuana, opioids, methamphetamines).⁹ The study found inpatients are three times more likely to complete treatment than outpatients.

2. What are the evidence-based guidelines associated with inpatient and outpatients treatment programs in adults with sub stance use disorders?

The evidence-based guidelines from British Columbia Ministry of Health on opioids use disorder¹⁰ recommend:

“If withdrawal management is pursued, for most patients, this can be provided more safely in an outpatient rather than inpatient setting.” (p 12) (Quality of evidence: moderate; Strength of recommendation: strong). The recommendation was based on evidence from Cochrane SRs on the use of medication such as methadone, buprenorphine and adrenergic agonists for the management of opioid withdrawal, and committee consensus that community-based outpatient withdrawal management should be offered. It was stated that outpatient treatment allows for an individualized approach to therapy and may be less disruptive to patients and their families than inpatient treatment.

“For patients wishing to avoid long-term opioid agonist treatment, provide supervised slow (> 1 month) outpatient or residential opioid agonist taper rather than rapid (< 1 week) inpatient opioid agonist taper.” (p 13) (Quality of evidence: low; Strength of recommendation: weak). The authors believe that the slow approach permits a slower, more flexible and individualized approach to tapered agonist reduction, and allows for dose adjustment and stabilization in case withdrawal symptoms occur.

The main findings of the included studies are presented in Appendix 4.

Limitations

Findings from the included narrative SR need to be interpreted with caution as data were from two studies with no quality assessment provided. Generalizability of the findings is limited in the trial that included only patients with high alcohol involvement; patients in both groups this trial had additional outpatient care, making the comparison between inpatient and outpatient treatment not pure. Differences in baseline patient characteristics in the two groups in another included trial may lead to biased interpretation of the findings. Evidence on substance use disorder was found in one study in which the authors agreed that differences in the main outcome definitions (i.e., “successful completion”) varied across programs, which presented a limitation of this study.

Conclusions and Implications for Decision or Policy Making

For patients with alcohol use disorders, better detoxification completion and abstinence rates, and similar adverse event rates, were found in outpatient care compared to inpatient care in a couple of studies with short follow-up periods (one to two months). One study with a longer follow-up period found inpatients consumed less alcohol than outpatients in the year after entering treatment. This may be explained by the controlled environment of inpatient care that avoids the distractions that could be present in an outpatient care situation. In patients with severe alcohol dependence, data from one study found initial but decreasing benefit of inpatient over outpatient care across time in alcohol abstinence. For patients with substance use disorders, data from one study showed inpatients are more likely to complete treatment than outpatients. The small number of studies found and their heterogeneity in design and reported outcomes cautioned the interpretation of the findings.

The evidence-based guidelines from British Columbia Ministry of Health on opioids use disorder recommend that withdrawal management, if needed, can be provided more safely in an outpatient setting rather than in an inpatient setting in most patients. For patients who wish to avoid long-term opioid agonist treatment, supervised slow (longer than one month) outpatient or residential opioid agonist taper can be provided rather than rapid (less than one week) inpatient opioid agonist taper. The slow approach may permit a more flexible and individualized approach to tapered agonist reduction, which allows dose adjustment and stabilization in case withdrawal symptoms occur.

A systematic review on patients’ preferences to treatment for substance use disorders found the majority of patients preferred outpatient treatment over inpatient treatment, though the reasons for this preference were not explored in this review.¹¹ This renders shared decision making an important process in the treatment of patients with substance use disorders. Development and implementation of a protocol for evaluation and treatment of patients requesting alcohol detoxification may be important to standardize the care and choice between inpatient versus outpatient treatment.¹²