Results Summary

What was the research about?

Addiction is a treatable, long-term illness that affects a person’s brain and behavior. It leads to an inability to control the use of substances, such as drugs or alcohol. People with addiction continue to use substances despite the harm it causes. Treatment can be in different care settings, such as outpatient or residential programs.

The American Society of Addiction Medicine, or ASAM, created a standard approach to match patients to treatment. Patients answer a comprehensive set of questions about their withdrawal symptoms, physical and mental health, readiness to change, and chance of relapse. Questions also ask about living situation and relationships. Based on the responses, the ASAM approach suggests a treatment setting.

In this study, the research team wanted to learn whether using ASAM standards worked to help patients with addiction stay in treatment. The team compared data from patients in addiction programs in:

  • 30 counties that began requiring use of ASAM standards, versus
  • 28 counties that didn’t require ASAM standards

The research team also did surveys to look at patients’ experiences and the information received at the start of treatment.

What were the results?

Across treatment settings, counties that required ASAM standards had an increase in the number of patients who stayed in residential treatment programs for at least 30 days. But these counties had no difference in the number of patients who stayed in outpatient treatment programs.

In survey responses, compared with patients in programs that didn’t use ASAM standards, patients in programs that used them were more likely to report that the person asking questions discussed:

  • Withdrawal symptoms and the need for management
  • Reasons for and problems from continued substance use
  • What might make it easier or harder to recover
  • What they learned from patients’ answers to questions
  • Treatment recommendations

Patients also understood more about their mental and physical health. They were more satisfied with their treatment setting choice. Patients didn’t differ in responses to other survey questions, such as whether staff listened carefully.

What did the research team do?

The research team used a database with information from patients treated at all addiction programs in California that had received public funding. All patients had Medicaid. The team looked at discharge and treatment records to compare counties.

To assess patient views, the research team surveyed 851 patients in addiction programs that did and didn’t use ASAM standards.

People with addiction, caregivers, addiction doctors, and patient advocates helped design the study.

What were the limits of the study?

The research team didn’t assign patients or counties by chance to use ASAM standards so factors other than the standards may have affected the results. The study took place in California. Results may differ for patients in other states.

Future research could look at how to help patients feel comfortable answering the comprehensive ASAM questions at the start of treatment.

How can people use the results?

Addiction treatment programs can use the results when considering ways to match patients with the treatment setting that works best for them.

Final Research Report

View this project's final research report.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers noted that the report focused primarily on positive study results, indicating improved retention in substance abuse treatment for California counties implementing American Society of Addiction Medicine (ASAM) criteria for treatment intake compared to counties that did not use this approach, with little attention to negative study results that were also important. The researchers pointed out that they did discuss the potential reasons for negative results, in particular that whether or not ASAM-based intakes were used did not affect retention when patients started outpatient treatment before moving to residential.
  • Reviewers also felt that the researchers should discuss how this natural experiment study design could result in alternative explanations for their study results, for instance that counties that did not implement ASAM criteria were able to use larger residential centers with more patient beds than counties not implementing these criteria. The researchers reported that there were no differences in residential center capacity so this could not explain treatment retention differences between the two comparison groups of counties.
  • The reviewers asked the researchers whether they omitted Los Angeles County treatment centers, which implemented a computerized ASAM-based intake process, from the main comparison of ASAM-based versus non-ASAM-based intake procedures because of the incomplete data researchers received from that county. The researchers confirmed that they had originally intended to omit the computerized procedures from the comparison and did not do so only as a result of the missing data. In the report, the researchers stated that the data from the computerized assessment were found to be unreliable.
  • Similarly, the reviewers noted that the researchers described retention outcomes separately for patients in residential settings from patients who started in outpatient settings, but there was no reference to this differentiation in the study specific aims. The reviewers asked the researchers to clarify the results for the full sample as described in the study aims, rather than separately for these two groups based on treatment intensity. The researchers explained that since the study goal was to determine whether proper treatment placement would improve retention rates, it should be assumed that they would want to look at patients based on the level of care they received after the ASAM-based intake.

Project Information

Tami L. Mark, PhD, MBA
RTI International
Comparative Effectiveness of Clinical Decision-Making Processes Required by Public Health Systems

Key Dates

November 2017
June 2022

Study Registration Information


Has Results
Award Type
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: March 30, 2023