Sixty-eight studies (37 RCTs) were included in the review. The total number of participants was unstated.
Education: Ten studies (two RCTs) were included in this category. There was a large variation in study quality. Only one study reported adequate sample sizes. Eight study interventions were delivered by specialist researcher /clinicians and two included nurses. Nine interventions had a favourable impact on a carer's knowledge and one did not. One study reported a reduction in distress and four studies found no effect on stress.
Supportive family education: Thirteen studies (seven RCTs) were included in this category. Nurses delivered interventions in two studies and were part of a multidisciplinary team in a further study. The other study interventions were delivered by a specialist researcher/clinicians. There was wide variation in intervention components. Five out of six studies reported a reduction in carer burden as a result of the intervention. Three out of four studies found improvements in carer knowledge. Findings on mental or physical health were mixed.
Family interventions: Twenty-nine studies (19 RCTs) were included in this category. Most studies had small sample sizes. In eight studies interventions were delivered by mental health nurses and in five by nurses as part of a mental health team. Behaviour family therapy was studied in 12 out of 29 studies and most reported improvements in either knowledge or burden and some improvements in the mental health of carers were noted. Cognitive behaviour therapy was less effective in reducing carer burden and improving mental health and there was equivocal evidence for other types of family intervention.
Community support services: Nine studies (six RCTs) were included in this category. All support interventions were delivered by multidisciplinary teams that included nurses. Five out of seven studies found a reduction in burden. Interventions that were theoretically based showed the greatest promise. Other outcomes (reported more sparsely) did not tend to find a benefit of the interventions.
Mutual support groups: Four studies (two RCTs) were included in this category. Interventions were delivered by specialist researchers in all studies except one. Improvements were noted in burden, mood, health, coping and knowledge.
Day care services: Three studies (one RCT) were included in this category. All interventions included nurses in the delivery of these services. There was no evidence that day care significantly impacted on carer burden or health.