BackgroundRandomised controlled trials suggest that family therapy has a positive effect on the course of depression, schizophrenia and anorexia nervosa. However, it is largely unknown whether a positive link also exists between caregiver involvement and patient outcome in everyday psychiatric hospital care, using information reported directly from patients, i.e. patient-reported experience measures (PREM), and their caregivers. The objective of this study is to examine whether caregiver-reported involvement is associated with PREM regarding patient improvement and overall satisfaction with care.MethodsUsing data from the National Survey of Psychiatric Patient Experiences 2018, we conducted a nationwide cross-sectional study in Danish psychiatric hospitals including patients and their caregivers who had been in contact with the hospital (n = 940 patients, n = 1008 caregivers). A unique patient identifier on the two distinct questionnaires for the patient and their caregiver enabled unambiguous linkage of data. In relation to PREM, five aspects of caregiver involvement were analysed using logistic regression with adjustment for patient age, sex and diagnosis.ResultsWe consistently find that high caregiver-reported involvement is statistically significantly associated with high patient-reported improvement and overall satisfaction with care with odds ratios (OR) ranging from 1.69 (95% confidence interval (CI) 0.95–2.99) to 4.09 (95% CI 2.48–6.76). This applies to the following aspects of caregiver-reported involvement: support for the patient-caregiver relationship, caregiver information, consideration for caregiver experiences and the involvement of caregivers in decision making. No statistically significant association is observed regarding whether caregivers talk to the staff about their expectations for the hospital contact.ConclusionThis nationwide study implies that caregiver involvement focusing on the patient-caregiver relationship is positively associated with patient improvement and overall satisfaction with care in everyday psychiatric hospital care.