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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.

For adults in critical care, a complex psychological intervention delivered by nurses did not reduce the severity of post-traumatic stress disorder (PTSD) symptoms at six months, compared with usual care. The intervention included creating a therapeutic environment, three stress support sessions, and a relaxation/recovery programme. A cost-effectiveness evaluation showed great uncertainty over whether the programme was value for money.

The intervention was developed using the limited evidence that was available about how to help critical care patients. This NIHR-funded project incorporated feasibility and pilot studies, as well as a large randomised controlled trial at 24 NHS sites.

The results of the study mean that this particular intervention should not be introduced to the NHS.

But the research confirmed the problem. Two-thirds of the critical care patients in this study experienced high levels of anxiety, which is a greater proportion than previously reported. One in five patients showed longer-term symptoms of PTSD. This study gives some valuable insights and suggestions for the development of future interventions.

Why was this study needed?

Each year more than 170,000 adults are admitted to general critical care units in the NHS. About half of those patients experience acute stress, and about two-thirds experience hallucinations and delusions. Around 25% of those who survive their illness develop PTSD during the first six months after discharge from critical care.

The authors previously developed the complex psychological intervention. This included creating a therapeutic ward environment; reducing stressors such as loud noise, increasing awareness of psychological stress and improving communication and a sense of hope. Individual stress support sessions were based on cognitive behavioural therapy. Finally, the relaxation and recovery programme included information and advice on how to cope with emotions after discharge plus breathing and meditation exercises.

As there is limited evidence about what could prevent PTSD, these researchers conducted feasibility and pilot studies of the intervention before carrying out a cluster randomised controlled trial to evaluate it.

What did this study do?

The trial aimed to recruit 24 adult general critical care units in England, Wales and Northern Ireland to a cluster randomised trial with at least 1,378 patients. There was a baseline (pre-intervention) period and a staggered roll-out of the intervention to half of the units. Twelve control group sites delivered usual care (patients receiving psychological support or treatment at clinicians’ discretion).

Twelve sites provided the intervention following online training for all staff to create the therapeutic environment.

Patients in the intervention sites were screened using the Intensive care Psychological Assessment Tool (IPAT). If they were acutely stressed, they received three stress support sessions and the relaxation and recovery programme, delivered by three nurses trained over three days. All patients were assessed for PTSD symptoms after six months.

A limitation is that three days of training may not have been sufficient to deliver the psychological intervention, which might have reduced the effectiveness of the program.

What did it find?

  • Out of 313 participants assessed by IPAT, 199 were identified as acutely stressed and were eligible to receive the stress support sessions; 64% received all three sessions, 16% received two sessions, 10% received one, and 9% didn’t have any sessions. The 171 participants who received at least one stress session were given the relax and recover package to use, and 77% reported using it.
  • According to the PTSD Symptom Scale (PSS-SR) questionnaire (range from 0 to 51, with 18 or more indicating likely PTSD), the mean scores were similar and barely changed. The intervention group mean score was 11.8 at baseline period and 11.5 after six months compared with 10.1 and 10.2 for the control group.
  • At six months, 24% of the intervention group and 18% of the control group scored 18 or more on the PSS-SR, which indicates that symptoms are severe enough to warrant further PTSD investigation.
  • The cost-effectiveness analysis showed that on average, the intervention decreased costs and slightly improved QALYs (Quality Adjusted Life Years). This resulted in a positive incremental net benefit at six months (£835, 95% confidence interval £4,322 to £5,992). But there is considerable statistical uncertainty surrounding these results.

What does current guidance say on this issue?

NICE published a guideline in 2009 on rehabilitation after critical illness in adults. This says that patients should be assessed while in a critical care unit to determine their risk of developing physical and non-physical morbidity, which includes PTSD. If at risk, rehabilitation goals should be agreed and rehabilitation started as early as clinically possible.

Rehabilitation should include preventative measures, an individualised programme and frequent follow-up reviews. If PTSD is suspected at subsequent assessments, clinicians are referred to NICE’s guideline on PTSD for recommendations on assessment and management.

What are the implications?

This intervention in its current form should not be adopted into routine practice. It did not reduce the symptoms of PTSD six months after patients were admitted to a critical care unit. It was also very uncertain if the intervention was cost-effective.

However, it is the first trial of its kind in critical care and the authors identified reasons for why it may not have worked. These include the timing of the intervention as patients may have been too ill to benefit from therapy, patients being discharged before the intervention was complete, and nurses not always being comfortable delivering the sessions. The results and analyses could be used to help develop future interventions. Data from this study confirmed the high levels of acute anxiety experienced by patients in critical care and the need for greater support.

Citation and Funding

Mouncey PR, Wade D, Richards-Belle A et al. A nurse-led, preventive, psychological intervention to reduce PTSD symptom severity in critically ill patients: the POPPI feasibility study and cluster RCT. Health Services and Delivery Research. 2019:7(30).

This project was funded by the NIHR Health Services and Delivery Research Programme (project number 12/64/124).



NHS website. Intensive care. London: Department of Health and Social Care; 2019.

NICE. Post-traumatic stress disorder. NG116. London: National Institute for Health and Care Excellence; 2018.

NICE. Rehabilitation after critical illness in adults. CG83. London: National Institute for Health and Care Excellence; 2009.

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Adult general critical care units were defined as intensive care units or combined intensive care/high-dependency units. Standalone high-dependency units and specialist critical care units (e.g. neurosciences, cardiothoracic) were not eligible for participation in the cluster RCT.