Long term institutional or residential treatment of patients with substance abuse compared to short-term outpatient treatment

The objectives were to assess the effects of the following interventions: 1) to compare the effectiveness of long-term treatment of patient with substance abuse compared to short-term treatment. 2) To estimate the cost-effectiveness of long-term compared to short-term treatment.

Methods
We conducted a systematic literature search in March 2008 (updated in February 2009) in the following electronic databases: Medline, Embase, Cochrane Library, PsychInfo, Cinahl, Social Services Abstracts, Sociological Abstracts, Eric, International Bibliography of the Social Sciences, Social Sciences Citation Index, Social Care Online, C2-SPECTR, SveMed+, BiblioMap, Bibsys and Google Scholar. Predefined criteria of study quality are appraised according to the Knowledge Centre’s methodological handbook.

We searched for systematic reviews, randomised controlled trials, prospective cohort studies and economic evaluations according to predefined inclusion criteria. To be included a study had to present results about effects of long term treatment in institutions or residential drug abuse treatment. The treatment program had to serve patients with substance use disorder. We summarized the reported results and assessed the quality of the evidence. One systematic review and five primary studies are included in this report.  

Results
We found several studies that reported a comparison of inpatient versus outpatient treatment. The systematic review showed little evidence that long-term treatment such as therapeutic communities (TC) offer significant benefits in comparison with other residential treatment, or that one type of TC is better than another. Three months compared with six months programmes within modified TC showed higher completion rates in the three months programme. Six months compared with 12 months standard TC with retention rate (40 days) was significantly greater with the 12 months than the six months programme.

For prospective cohort studies, the reduction in prevalence of cocaine use in the year after treatment was associated with longer treatment durations (+ 6 months) in Long Term Residential (LTR) and Outpatient Drug Free (ODF) treatment. In addition, reductions in illegal activity and increase in full time employment were related to treatment stays more than 6 months. The threshold of treatment effect was 90 days, and it lasted for up to 270 days. After this interval, the effect of the treatment declines. There were fewer relapses to drug abuse in the group of outpatient drug free treatment than in the long term residential treatment.

Controlling for multiple factors, treatment duration had a positive linear relationship with primary drug use improvement among methadone clients and an inverted-U-shaped relationship as a function of time  with overall and primary drug use improvements among out-patient and long-term residential clients. Improvement with longer duration is greatest for long-term residential clients. Greater service intensity and satisfaction were positively related to either treatment completion or longer treatment retention, which in turn was related to favourable treatment outcomes. Patients with greater problem severity received more services and were more likely to be satisfied with treatment. These patterns were similar for patients regardless of whether they were treated in outpatient drug-free programs or residential programs.

Only two cost-benefit analyses were included to describe health economic consequences of long-term treatment of substance abuse compared to short term treatment. The first study estimated benefit to cost ratios of long-term residential treatment and outpatient drug-free treatment, while the second also considered the cost-effectiveness of short term inpatient treatment. The first study estimated benefit to cost ratios of 1,68-2,73 and 1,33-3,26 for long-term treatment and outpatient treatment respectively, concluding that both treatment modalities provided evidence of significant returns on these treatment investments for cocaine addiction. The second were more focused on quantifying the economic benefit of increased treatment duration and intensity in residential and outpatient treatment settings. The study calculated the economic benefit from an additional day of treatment to be on average of $5 for long-term residential treatment, $13 for outpatient drug-free treatment and $21 for short-term residential treatment. These benefits yielded 9%, 94% and 29% of the cost of an additional day of care respectively, suggesting that outpatient and short-term residential treatments might be cost effective compared to long-term residential treatment. However, it was emphasized that the results must be interpreted carefully.

Conclusion
Our systematic review gave no compelling evidence to support long term addiction treatment over short term treatment. However, it was emphasized that the results must be interpreted carefully, because of low quality for economic studies. Results from future research may alter our conclusions.