Critical time intervention for people leaving prison at risk of homelessness in England and Wales (PHaCT trial): a pilot feasibility randomised controlled trial

  • Adam Dale Newman Williams
  • , Nina Jacob
  • , Detelina Grozeva
  • , Barry Lloyd
  • , Yvonne Moriarty
  • , Manuela Deidda
  • , Samuel Owusu Achiaw
  • , Ian Thomas
  • , Kelly Lewis
  • , Rebecca Cannings-John
  • , Iolo Madoc-Jones
  • , Suzanne Fitzpatrick
  • , Srinivasa Vittal Katikireddi
  • , Peter Mackie
  • , James White
  • , Jim Lewsey

Research output: Contribution to journalArticlepeer-review

2 Downloads (Pure)

Abstract

OBJECTIVE: To determine whether a full-scale randomised control trial (RCT) assessing the efficacy and cost-effectiveness of a housing led Critical Time Intervention (CTI) is feasible and acceptable. DESIGN: Pilot parallel two-arm individual level RCT, including process evaluation and embedded exploratory health economic evaluation.

SETTING: Four prisons for men across England and Wales, UK.

PARTICIPANTS: Men leaving prison at risk of homelessness and intervention delivery staff. 

INTERVENTION: CTI has four components: (1) pre-engagement phase: assessing the needs of the client and implementing a plan pre-discharge; (2) transition to community: forming relationships and goal setting; (3) try out: encouraging problem-solving and managing practical issues and (4) transfer of care: developing long-term goals and transferring responsibilities to community providers.

OUTCOME MEASURES: Progression criteria: recruitment, retention, acceptability of the processes (CTI and trial method) and fidelity of intervention delivery. We also assessed the completeness of primary, secondary and exploratory outcome measures and estimated intervention costs.

RESULTS: The recruitment progression criterion was met, with 92% (34/37) of approached individuals consenting to participate (target: 50%). However, the overall recruitment target of 80 was not achieved, and retention was low, only 18% (6/34) provided follow-up data, well below the 60% threshold. Retention was hindered by systemic challenges, including changes to prison release policies and reduced probation support. While the CTI model was acceptable to staff and service users, the trial design, particularly randomisation, was not. Intervention fidelity met the progression criteria. Baseline data collection for health economics and resource use was feasible, and intervention costs were estimated. 

CONCLUSION: This pilot trial identified significant challenges to conducting a full-scale RCT of CTI in this context, particularly around retention, trial acceptability and systemic instability. While CTI remains a promising model, a traditional RCT design may not be viable in this setting without substantial structural and ethical adaptations.

TRIAL REGISTRATION NUMBER: ISRCTN46969988.

Original languageEnglish
Pages (from-to)e097753
JournalBMJ Open
Volume15
Issue number12
DOIs
Publication statusPublished - 17 Dec 2025

Keywords

  • Feasibility Studies
  • Prisons
  • Quality of Life
  • Randomized Controlled Trial
  • Vulnerable Populations

ASJC Scopus subject areas

  • General Medicine

Fingerprint

Dive into the research topics of 'Critical time intervention for people leaving prison at risk of homelessness in England and Wales (PHaCT trial): a pilot feasibility randomised controlled trial'. Together they form a unique fingerprint.

Cite this