Evaluation of a Complex Intervention for Prisoners with Common Mental Health Problems, Near To and After Release: The Engager Randomised Controlled Trial

Richard Byng, Tim Kirkpatrick, Charlotte Lennox, Florian Walter, Robert Anderson, Sarah Louise Brand, Lynne Callaghan, Lauren Carroll, Graham Durcan, Laura Gill, Sara Goodier, Jonathan Green, Rebecca Greer, Mark Haddad, Tirril Harris, William Henley, Rachael M Hunter, Sarah Leonard, Mike Maguire, Susan MichieChristabel Owens, Mark Pearson, Cath Quinn, Sarah Rybczynska-Bunt, Caroline Stevenson, Amy Stewart, Alex Stirzaker, Roxanne Todd, Florian Walter, Lauren Weston, Nat Wright, Rod Taylor

Research output: Working paperPreprint


Background: Many male prisoners have significant mental health problems, including anxiety and depression. High proportions struggle with with homelessness and substance misuse. Only a minority receive specialist mental health care, including on release from prison. Few theoretically informed interventions have been developed to address these complex needs, and none formally evaluated. This study tests the hypothesis that the Engager intervention improves mental health outcomes following release.

Methods: Two group parallel randomised superiority trial conducted in the North West and South West of England between in 2016-19. Men serving a prison sentence of two years or less were individually allocated 1:1 to either intervention (Engager plus usual care) or the control (usual care alone) group. Engager included psychological and practical support in prison, on release, and for three to five months in the community. Primary outcome: Clinical Outcomes in Routine Evaluation Outcome Measure (CORE-OM), six months after release. Primary analysis compared groups based on intention to treat (ITT).

Outcomes: A total of 280 men were randomised out of the 396 who were potentially eligible and agreed to participate; 105 did not meet the mental health inclusion criteria. There was no mean difference in either the ITT complete case analysis between groups (92 in each arm) for change in the CORE-OM score (1·1, 95% confidence interval -1·1 to 3·2, p= 0·325) or secondary analyses. There were no consistent clinically significant between group differences for secondary outcomes. Full implementation and delivery were not achieved with 18% receiving no post release intervention.

Interpretation: Engager is the first trial of a collaborative care intervention adapted for prison leavers. The intervention was not effective using standard outcome measures. Future research may benefit from improved delivery and more sensitive outcomes measures.

Trial Registration: Engager was a two group parallel randomised superiority trial (ISRCTN11707331)

Funding: Funding for the study was provided by the NIHR Programme Grants for Applied Research (grant number: RP-PG-1210-12011)

Declaration of Interest: None to declare.

Ethical Approval: The study was approved by the UK National Health Service, Wales Research
Ethics Committee 3 (ref: 15/WA/0314), and the National Research Committee of Her Majesty’s Prison and Probation Service.
Original languageEnglish
PublisherThe Lancet
Number of pages20
Publication statusPublished - 21 Sept 2021

Publication series

NameSSRN Electronic Journal
PublisherSocial Science Research Network
ISSN (Print)1556-5068


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