Cox 2018a.

Methods	Design: multisite RCT
Participants	Setting: hospital ICUs Type of trauma exposure: patients admitted to an ICU who had been in receipt of mechanical ventilation for > 48 consecutive hours. Inclusion criteria: aged ≥ 18 years of age and in receipt of mechanical ventilation for > 48 consecutive hours, and successful extubation before discharge. Exclusion criteria: pre‐existing or current cognitive impairment; treatment for severe mental illness during the 6 months preceding admission (e.g. active psychosis, suicidality); residence at a location other than home immediately before admission,; poor English fluency; ICU attending physician's expectation of patient survival < 3 months; inability to complete study procedures as determined by study staff; and failure to return home from either a hospital or postacute care facility within 3 months after discharge. Exclusion criteria for family members included history of cognitive impairment and poor English fluency. Sample size: 2002 patients assessed for eligibility; 175 randomised Mean age: 51.73 (SD 13.76) years Gender: 100 (57.1%) men; 75 (42.9%) women Ethnicity: 21.7% African‐American; 70.1% white; 1.1% Asian; 1.1% American Indian/Alaska Native; 0.6% Native Hawaiian or other Pacific Islander; 1.1% Hispanic; 0.6% did not know or did not wish to answer. Country: USA
Interventions	Group 1: telephone‐ and web‐based CBT‐based coping skills training: n = 86 CBT intervention delivered in 6 weekly telephone sessions, each lasting approximately 30 min, that addressed the following: introduction and relaxation exercise; progressive muscle relaxation; pleasant activities and activity–rest cycle; communication; cognitive restructuring and pleasant imagery; review and planning for sustainability. Psychologists taught each skill by providing a description and rationale for its use, leading participants through practice with feedback in the context of any self‐reported ongoing stressors, helping participants plan how to apply the skill in real life, and highlighting relevant web‐based content. In addition to learning skills themselves, family members coached patients in applying skills and using the web content on a day‐to‐day basis. Group 2: education programme: n = 89 An education programme was designed with the help of a stakeholder group to address poor comprehension of critical illness, omitting any mention of post‐ICU psychological distress. Programme consisted of 6 informational videos with accompanying web‐based content. Study staff with content expertise in critical illness conducted 2 × 30‐min telephone calls with participants during the 6‐week intervention period to review materials and answer related questions.
Outcomes	PTSD: IES‐R Other: HADS; EQ‐5D; global mental and physical health status assessed with the PROMIS; adaptive coping behaviours measured by the Brief COPE. Follow‐up: 3 months' postbaseline (immediately post‐treatment), and 6 months' postbaseline (3 months' post‐treatment).
Notes	Family members of participants were also included and randomised to both interventions. The data reported here are for patient participants only. Eight participants died during the study. Patients were, on average, middle‐aged and severely ill, with an expected hospital mortality of approximately 50%. Approximately one‐third of patients had been treated for depression, anxiety or PTSD in the 3 months preceding admission. Readmission occurred among 43 (25%) patients during follow‐up.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation was undertaken via a password protected computerised system allocated patient–family member dyads at a 1:1 treatment group ratio with blocks of 4, stratifying by 3 factors to ensure balance.
Allocation concealment (selection bias)	Low risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Trained research coordinators blinded to treatment group collected clinical data. Participants completed study surveys by telephone with treatment group‐blinded University coordinators or by a password‐protected electronic patient‐reported outcomes system at baseline and follow‐up.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Analyses were conducted according to the ITT principle. Primary and secondary survey outcome analyses were conducted with full likelihood methods.
Selective reporting (reporting bias)	Low risk	Results reported as described in preregistered protocol.
Other bias	High risk	Study conducted with a severely ill population with high levels of premorbid mental health problems. The authors observed higher‐than‐expected attrition, attributable primarily to patients' serious illnesses and occurring after consent but before randomisation. Adherence to the interventions was fairly low and partly attributed to illness.