Predictors, moderators and mediators of carer distress and maintaining factors in eating disorders

Background: Carers of people with eating disorders (EDs) have heightened levels of distress, expressed emotion, burden and accommodation to the ED; factors implicated in maintenance of the ED. Although carers’ skills interventions are helpful, how they effect change, and the processes involved in hypothesised relationships between ED symptoms and carer distress, is unclear.
Aims: To determine the processes involved in the beneficial carer and service-user outcomes from a carers’ skills randomised controlled trial (RCT), including by longitudinally examining relationships between ED symptoms and carer distress.
Method: This study utilised archival data from a multi-site pragmatic carers’ skills RCT. Primary carers (159) of people presenting for Anorexia Nervosa hospital treatment were randomly allocated to the intervention or treatment as usual. Moderators and mediators of intervention outcomes, and of longitudinal relationships between ED symptoms and carer distress, were examined.
Results: The positive association between intervention and reduction in expressed emotion was significant only when more than one carer was involved per service-user. Reductions in expressed emotion and burden statistically mediated positive relationships between intervention and reduction in carer and ED outcomes. Findings from longitudinal mediation models were consistent with positive indirect associations between ED symptoms (at discharge) and carer distress (at six-month follow-up), and between carer distress (at baseline) and ED symptoms (at 12-month follow-up), mediated by carer and service-user factors.
Limitations & Implications: Missing data may have introduced bias. Accessing only primary carers of severely unwell service-users limited generalisability. Results support the importance of carers’ skills interventions in addressing ED-related service-user and carer difficulties.