Results Summary

What was the research about?

Opioid use disorder, or OUD, is a pattern of using opioids, such as prescription medicines or heroin, that can lead to addiction or overdose. In 2018, about 128 Americans died every day from an opioid overdose. OUD is common among people entering jail.

In this study, the research team wanted to learn whether starting treatment with naltrexone before leaving jail or receiving referrals for treatment after leaving jail helped reduce rates of OUD relapse. Naltrexone is a medicine that blocks the effects of opioids, reduces opioid cravings, and prevents relapse and overdose deaths. A full course is four shots with four weeks between each shot.

What were the results?

Only 21 of the 86 people in the study remained on naltrexone after three months. As a result, the research team can’t be sure whether starting treatment before or after leaving jail was more effective in reducing relapse rates.

Overall, relapse rates didn’t differ between people who started treatment before leaving jail and those who received referrals for treatment. People who started treatment before their release were more likely to go back to jail within three months than those who got referrals.

Who was in the study?

The study started with 146 people in the Philadelphia County jail. Of these, 53 percent were white, 25 percent were Hispanic, and 20 percent were black. The average age was 37, and 73 percent were men. Because of uncertainty about release dates, 60 people dropped out of the study before receiving treatment or referrals.

What did the research team do?

The research team assigned people in the study by chance to one of two groups. One group got their first naltrexone shot before leaving jail. The other group received referrals to get their first shot at the study’s partner clinic after leaving jail. The team offered both groups monthly follow-up shots and weekly group therapy and one-on-one counseling sessions. These sessions included education about addiction, ways to prevent relapse, and ways to deal with negative emotions.

At follow-up appointments, people in the study took urine drug tests and completed surveys on whether they had relapsed. Because many people didn’t attend their appointments, the research team created a phone survey to collect more relapse data. The team used these data to confirm whether 63 people had relapsed.

People who had been in jail, clinicians, and government officials helped design the study and advised the research team.

What were the limits of the study?

Fewer people enrolled in the study than planned and the dropout rate was high. These factors limited the research team’s ability to see differences between the groups.

Future research could look into ways to help people with OUDs continue treatment after leaving jail.

How can people use the results?

Criminal justice systems could look at these results when considering ways to treat OUD among people who are leaving jail.

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 asked for more information regarding the patient-centeredness of the study, indicating that there was not enough information about how community stakeholders supported the study and how the prisoner stakeholders contributed their thoughts and perspectives. The researchers added information to the report about the study’s community advisory board, which included people who work in probation and parole departments and who provided advice on how to integrate the study into ongoing operations. The researchers also described their monthly meetings with prisoners during which they presented the study and distributed related information. They included in the report examples of the conversations the researchers had with prisoner participants to demonstrate participants’ acceptance of the intervention. In addition, the researchers explained that they met with other stakeholders, including public defenders and their social work staff and judges.
  • The reviewers asked for greater clarity on how the project departed from the intention-to-treat principle, how that affected analysis and how the results can be interpreted. The researchers explained that although they randomized to the before release  and after release  groups, 60 participants in the before release  group were lost before they could enter the study. This was due to the difficulties working in the jail setting because prisoner release would sometimes be delayed for weeks or would happen very quickly before the investigators could deliver the intervention. During the lag time, some changed their minds about participating and others’ plans changed because of decisions about sentencing. These difficulties reduced the number of study participants dramatically, and these people were not included in further analyses because they were never in a position to receive treatment. However, the researchers said the high rate of dropout after beginning treatment and high rates of missing data more seriously threatened the validity of the analyses.  They adjusted their primary outcome and added statistical tests to try to accommodate missing responses. The researchers noted that the departure from the intention-to-treat principle reduced the power of the study to compare results but did not appear to create bias in any comparisons.
  • The reviewers noted that secondary outcomes from the original research plan were not included in the results. The reviewers also asked the researchers to provide more justification for replacing some of their outcome measures, such as using number of naltrexone injections rather than number of treatment visits. The researchers explained that they were not able to collect some data. In particular, patients who relapsed could not usually recall specifically when they relapsed. The researchers commented that the problem of significant missing data reduced confidence in all the planned secondary outcomes, except reincarcerations. The researchers also explained that the number of injections was chosen because it was a measure of treatment implementation as well as an objective measure of relapse since naltrexone injection could lead to opiate withdrawal if the participant has relapsed.

Conflict of Interest Disclosures

Project Information

George Woody, MD
University of Pennsylvania
Improving Outcomes of Opioid Addicted Prisoners with Extended Release Injectable Naltrexone Before Reentry

Key Dates

April 2015
September 2020

Study Registration Information


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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
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
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Last updated: January 25, 2023