Psychological outcomes following a nurse-led preventative psychological intervention for critically ill patients trial: Statistical and health economic analysis plan

A framework for extending trial design to facilitate missing data sensitivity analyses

BACKGROUND

Missing data are an inevitable challenge in Randomised Controlled Trials (RCTs), particularly those with Patient Reported Outcome Measures. Methodological guidance suggests that to avoid incorrect conclusions, studies should undertake sensitivity analyses which recognise that data may be 'missing not at random' (MNAR). A recommended approach is to elicit expert opinion about the likely outcome differences for those with missing versus observed data. However, few published trials plan and undertake these elicitation exercises, and so lack the external information required for these sensitivity analyses. The aim of this paper is to provide a framework that anticipates and allows for MNAR data in the design and analysis of clinical trials.

METHODS

We developed a framework for performing and using expert elicitation to frame sensitivity analysis in RCTs with missing outcome data. The framework includes the following steps: first defining the scope of the elicitation exercise, second developing the elicitation tool, third eliciting expert opinion about the missing outcomes, fourth evaluating the elicitation results, and fifth analysing the trial data. We provide guidance on key practical challenges that arise when adopting this approach in trials: the criteria for identifying relevant experts, the outcome scale for presenting data to experts, the appropriate representation of expert opinion, and the evaluation of the elicitation results.The framework was developed within the POPPI trial, which investigated whether a preventive, complex psychological intervention, commenced early in ICU, would reduce the development of patient-reported post-traumatic stress disorder symptom severity, and improve health-related quality of life. We illustrate the key aspects of the proposed framework using the POPPI trial.

RESULTS

For the POPPI trial, 113 experts were identified with potentially suitable knowledge and asked to participate in the elicitation exercise. The 113 experts provided 59 usable elicitation questionnaires. The sensitivity analysis found that the results from the primary analysis were robust to alternative MNAR mechanisms.

CONCLUSIONS

Future studies can adopt this framework to embed expert elicitation within the design of clinical trials. This will provide the information required for MNAR sensitivity analyses that examine the robustness of the trial conclusions to alternative, but realistic assumptions about the missing data.

Multiple session early psychological interventions for the prevention of post-traumatic stress disorder

BACKGROUND

The prevention of long-term psychological distress following traumatic events is a major concern. Systematic reviews have suggested that individual psychological debriefing is not an effective intervention at preventing post-traumatic stress disorder (PTSD). Over the past 20 years, other forms of intervention have been developed with the aim of preventing PTSD.

OBJECTIVES

To examine the efficacy of psychological interventions aimed at preventing PTSD in individuals exposed to a traumatic event but not identified as experiencing any specific psychological difficulties, in comparison with control conditions (e.g. usual care, waiting list and no treatment) and other psychological interventions.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO and ProQuest's Published International Literature On Traumatic Stress (PILOTS) database to 3 March 2018. An earlier search of CENTRAL and the Ovid databases was conducted via the Cochrane Common Mental Disorders Controlled Trial Register (CCMD-CTR) (all years to May 2016). We handsearched reference lists of relevant guidelines, systematic reviews and included study reports. Identified studies were shared with key experts in the field.We conducted an update search (15 March 2019) and placed any new trials in the 'awaiting classification' section. These will be incorporated into the next version of this review, as appropriate.

SELECTION CRITERIA

We searched for randomised controlled trials of any multiple session (two or more sessions) early psychological intervention or treatment designed to prevent symptoms of PTSD. We excluded single session individual/group psychological interventions. Comparator interventions included waiting list/usual care and active control condition. We included studies of adults who experienced a traumatic event which met the criterion A1 according to the Diagnostic and Statistical Manual (DSM-IV) for PTSD.

DATA COLLECTION AND ANALYSIS

We entered data into Review Manager 5 software. We analysed categorical outcomes as risk ratios (RRs), and continuous outcomes as mean differences (MD) or standardised mean differences (SMDs), with 95% confidence intervals (CI). We pooled data with a fixed-effect meta-analysis, except where there was heterogeneity, in which case we used a random-effects model. Two review authors independently assessed the included studies for risk of bias and discussed any conflicts with a third review author.

MAIN RESULTS

This is an update of a previous review.We included 27 studies with 3963 participants. The meta-analysis included 21 studies of 2721 participants. Seventeen studies compared multiple session early psychological intervention versus treatment as usual and four studies compared a multiple session early psychological intervention with active control condition.Low-certainty evidence indicated that multiple session early psychological interventions may be more effective than usual care in reducing PTSD diagnosis at three to six months' follow-up (RR 0.62, 95% CI 0.41 to 0.93; I2 = 34%; studies = 5; participants = 758). However, there was no statistically significant difference post-treatment (RR 1.06, 95% CI 0.85 to 1.32; I2 = 0%; studies = 5; participants = 556; very low-certainty evidence) or at seven to 12 months (RR 0.94, 95% CI 0.20 to 4.49; studies = 1; participants = 132; very low-certainty evidence). Meta-analysis indicated that there was no statistical difference in dropouts compared with usual care (RR 1.34, 95% CI 0.91 to 1.95; I2 = 34%; studies = 11; participants = 1154; low-certainty evidence) .At the primary endpoint of three to six months, low-certainty evidence indicated no statistical difference between groups in reducing severity of PTSD (SMD -0.10, 95% CI -0.22 to 0.02; I2 = 34%; studies = 15; participants = 1921), depression (SMD -0.04, 95% CI -0.19 to 0.10; I2 = 6%; studies = 7; participants = 1009) or anxiety symptoms (SMD -0.05, 95% CI -0.19 to 0.10; I2 = 2%; studies = 6; participants = 945).No studies comparing an intervention and active control reported outcomes for PTSD diagnosis. Low-certainty evidence showed that interventions may be associated with a higher dropout rate than active control condition (RR 1.61, 95% CI 1.11 to 2.34; studies = 2; participants = 425). At three to six months, low-certainty evidence indicated no statistical difference between interventions in terms of severity of PTSD symptoms (SMD -0.02, 95% CI -0.31 to 0.26; I2 = 43%; studies = 4; participants = 465), depression (SMD 0.04, 95% CI -0.16 to 0.23; I2 = 0%; studies = 2; participants = 409), anxiety (SMD 0.00, 95% CI -0.19 to 0.19; I2 = 0%; studies = 2; participants = 414) or quality of life (MD -0.03, 95% CI -0.06 to 0.00; studies = 1; participants = 239).None of the included studies reported on adverse events or use of health-related resources.

AUTHORS' CONCLUSIONS

While the review found some beneficial effects of multiple session early psychological interventions in the prevention of PTSD, the certainty of the evidence was low due to the high risk of bias in the included trials. The clear practice implication of this is that, at present, multiple session interventions aimed at everyone exposed to traumatic events cannot be recommended. There are a number of ongoing studies, demonstrating that this is a fast moving field of research. Future updates of this review will integrate the results of these new studies.

A nurse-led, preventive, psychological intervention to reduce PTSD symptom severity in critically ill patients: the POPPI feasibility study and cluster RCT

Background

High numbers of patients experience severe acute stress in critical care units. Acute stress has been linked to post-critical care psychological morbidity, including post-traumatic stress disorder (PTSD). Previously, a preventive, complex psychological intervention [Psychological Outcomes following a nurse-led Preventative Psychological Intervention for critically ill patients (POPPI)] was developed by this research team, to be led by nurses, to reduce the development of PTSD symptom severity at 6 months.

Objectives

The objectives were to (1) standardise and refine the POPPI intervention, and, if feasible, (2) evaluate it in a cluster randomised clinical trial (RCT).

Design

Two designs were used – (1) two feasibility studies to test the delivery and acceptability (to patients and staff) of the intervention, education package and support tools, and to test the trial procedures (i.e. recruitment and retention), and (2) a multicentre, parallel-group, cluster RCT with a baseline period and staggered roll-out of the intervention.

Setting

This study was set in NHS adult, general critical care units.

Participants

The participants were adult patients who were > 48 hours in a critical care unit, receiving level 3 care and able to consent.

Interventions

The intervention comprised three elements – (1) creating a therapeutic environment in critical care, (2) three stress support sessions for patients identified as acutely stressed and (3) a relaxation and recovery programme for patients identified as acutely stressed.

Main outcome measures

Primary outcome – patient-reported symptom severity using the PTSD Symptom Scale – Self Report (PSS-SR) questionnaire (to measure clinical effectiveness) and incremental costs, quality-adjusted life-years (QALYs) and net monetary benefit at 6 months (to measure cost-effectiveness). Secondary outcomes – days alive and free from sedation to day 30; duration of critical care unit stay; PSS-SR score of > 18 points; depression, anxiety and health-related quality of life at 6 months; and lifetime cost-effectiveness.

Results

(1) A total of 127 participants were recruited to the intervention feasibility study from two sites and 86 were recruited to the RCT procedures feasibility study from another two sites. The education package, support tools and intervention were refined. (2) A total of 24 sites were randomised to the intervention or control arms. A total of 1458 participants were recruited. Twelve sites delivered the intervention during the intervention period: > 80% of patients received two or more stress support sessions and all 12 sites achieved the target of > 80% of clinical staff completing the POPPI online training. There was, however, variation in delivery across sites. There was little difference between baseline and intervention periods in the development of PTSD symptom severity (measured by mean PSS-SR score) at 6 months for surviving patients in either the intervention or the control group: treatment effect estimate −0.03, 95% confidence interval (CI) −2.58 to 2.52; p = 0.98. On average, the intervention decreased costs and slightly improved QALYs, leading to a positive incremental net benefit at 6 months (£835, 95% CI −£4322 to £5992), but with considerable statistical uncertainty surrounding these results. There were no significant differences between the groups in any of the secondary outcomes or in the prespecified subgroup analyses.

Limitations

There was a risk of bias because different consent processes were used and as a result of the lack of blinding, which was mitigated as far as possible within the study design. The intervention started later than anticipated. Patients were not routinely monitored for delirium.

Conclusions

Among level 3 patients who stayed > 48 hours in critical care, the delivery of a preventive, complex psychological intervention, led by nurses, did not reduce the development of PTSD symptom severity at 6 months, when compared with usual care.

Future work

Prior to development and evaluation of subsequent psychological interventions, there is much to learn from post hoc analyses of the cluster RCT rich quantitative and qualitative data.

Trial registration

This trial is registered as ISRCTN61088114 and ISRCTN53448131.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 23, No. 30. See the NIHR Journals Library website for further project information.

Effect of a Nurse-Led Preventive Psychological Intervention on Symptoms of Posttraumatic Stress Disorder Among Critically Ill Patients: A Randomized Clinical Trial

IMPORTANCE

A meta-analysis of outcomes during the 6 months after intensive care unit (ICU) discharge indicate a prevalence for clinically important posttraumatic stress disorder (PTSD) symptoms of 25%.

OBJECTIVE

To determine whether a nurse-led preventive, complex psychological intervention, initiated in the ICU, reduces patient-reported PTSD symptom severity at 6 months.

DESIGN, SETTING, AND PARTICIPANTS

A multicenter, parallel-group, cluster-randomized clinical trial with integrated economic and process evaluations conducted in 24 ICUs in the United Kingdom. Participants were critically ill patients who regained mental capacity following receipt of level 3 (intensive) care. A total of 2961 eligible patients were identified from September 2015 to January 2017. A total of 2048 were approached for participation in the ICU, of which 1458 provided informed consent. Follow-up was completed December 2017.

INTERVENTIONS

Twenty four ICUs were randomized 1:1 to the intervention or control group. Intervention ICUs (n = 12; 669 participants) delivered usual care during a baseline period followed by an intervention period. The preventive, complex psychological intervention comprised promotion of a therapeutic ICU environment plus 3 stress support sessions and a relaxation and recovery program delivered by trained ICU nurses to high-risk (acutely stressed) patients. Control ICUs (n = 12; 789 participants) delivered usual care in both baseline and intervention periods.

MAIN OUTCOMES AND MEASURES

The primary clinical outcome was PTSD symptom severity among survivors at 6 months measured using the PTSD Symptom Scale-Self-Report questionnaire (score range, 0-51, with higher scores indicating greater symptom severity; the minimal clinically important difference was considered to be 4.2 points).

RESULTS

Among 1458 enrolled patients (mean [SD] age, 58 [16] years; 599 women [41%]), 1353 (93%) completed the study and were included in the final analysis. At 6 months, the mean PTSD Symptom Scale-Self-Report questionnaire score in intervention ICUs was 11.8 (baseline period) compared with 11.5 (intervention period) (difference, -0.40 [95% CI, -2.46 to 1.67]) and in control ICUs, 10.1 (baseline period) compared with 10.2 (intervention period) (difference, 0.06 [95% CI, -1.74 to 1.85]) between periods. There was no significant difference in PTSD symptom severity at 6 months (treatment effect estimate [difference in differences] of -0.03 [95% CI, -2.58 to 2.52]; P = .98).

CONCLUSIONS AND RELEVANCE

Among critically ill patients in the ICU, a nurse-led preventive, complex psychological intervention did not significantly reduce patient-reported PTSD symptom severity at 6 months. These findings do not support the use of this psychological intervention.

TRIAL REGISTRATION

ISRCTN53448131.