Patient-specific, time-varying predictors of post-ICU informal caregiver burden: the caregiver outcomes after ICU discharge project.

Background: The outcomes of informal caregivers of survivors of critical illness likely depend on patient characteristics, which may change over time. To date, few studies have examined patient-specific predictors of post-ICU informal caregiver burden, and none has tested whether predictors vary after hospital discharge.
Methods: We designed a prospective, longitudinal observational study, enrolling 48 patient-caregiver dyads from four ICUs in a university hospital. Informal caregiver depression symptoms were measured with the Center for Epidemiologic Studies Depression scale. Lifestyle disruption was measured with the Activity Restriction Scale. Linear regression models were built to test for patient- and caregiver-specific predictors of depression symptoms and lifestyle disruption 2, 6, and 12 months after ICU admission.
Results: Patients had a mean (SD) age of 52.5 (19.7) years, 67% were men, median (interquartile range) Acute Physiology and Chronic Health Evaluation score was 52 (38.5, 65). The caregivers had a mean (SD) age of 52.8 (12.8) years, 91.2% were women, and 48% were spouses. Predictors of caregiver depression symptoms were patient gender (men) at 2 and 12 months and tracheostomy at 12 months. Predictors of lifestyle disruption were patient education (more common among high school graduates) and patient gender (men) at 2 months, and tracheostomy, functional dependency, and patient gender (men) at 12 months.
Conclusions: The determinants of post-ICU informal caregiver burden likely depend on characteristics of the patient as well as the caregiver and may vary over time. Further research is necessary to better understand the longitudinal determinants of burden in order to develop more effective caregiver interventions.