Telephone-based peer support intervention to reduce depressive symptoms in women with coronary heart disease, a randomized controlled trial in Germany.

Depressive symptoms in patients with coronary heart disease (CHD) predict adverse outcomes regarding e.g. cardiovascular complications. We trained women with CHD to support female peers through telephone-based counseling and tested whether depressive symptoms can be reduced, and perceived social support can be improved by the intervention over six months. 108 women with CHD and self-reported depressive or anxiety symptoms were included in a randomized controlled trial. The intervention group was offered immediate telephone-based peer support for six months, while the waiting list control group received the intervention with a 6-months delay. Primary outcomes were depressive symptoms and perceived social support immediately after the intervention period and at 6-months-follow-up. 40% of the women made use of the peer support. During the first six months, both groups showed a reduction in depressive symptoms (IIG: t(169) = -1.79, p = .08; WCG: t(169) = -2.76, p = .007) and a significant improvement in social support (IIG: t(175) = 3.54, p < .001; WCG: t(175) = 3.36, p < .001). We found no significant group × time interactions. There was no influence of telephone-based peer support on depressive symptoms and social support. We discuss potential causes for both lack of specific treatment effects and the general improvement over time in both groups.