Objectives: To assess the evidence for the feasibility and effect of patient and familycentred care interventions provided in the intensive care unit, single or multicomponent, versus usual care, for reducing delirium, anxiety, depression and post-traumatic stress disorder in patients and family-members.

Design: A systematic review and meta-analysis following the PRISMA guidelines and GRADE approach. A systematic literature search of relevant databases, screening and inclusion of studies, data extraction and assessment of risk of bias according to Cochrane methodology. The study is preregistered on PROSPERO (CRD42020160768).

Setting: Adult intensive care units.

Results: Nine randomised controlled trials enrolling a total of 1170 patients and 1226 family-members were included. We found moderate to low certainty evidence indicating no effect of patient and family centred care on delirium, anxiety, depression, post-traumatic stress disorder, in-hospital mortality, intensive care length of stay or family-members' anxiety, depression and post-traumatic stress disorder. No studies looked at the effect of patient and family centred care on pain or cognitive function in patients. Evaluation of feasibility outcomes was scarce. The certainty of the evidence was low to moderate, mainly due to substantial risk of bias in individual studies and imprecision due to few events and small sample size.

Conclusion: It remains uncertain whether patient and family centred care compared to usual care may reduce delirium in patients and psychological sequelae of intensive care admission in patients and families due to limited evidence of moderate to low certainty. Lack of systematic process evaluation of intervention feasibility as recommended by the Medical Research Council to identify barriers and facilitators of patient and family centred care in the adult intensive care unit context, further limits the conclusions that can be drawn.