Relatives who care for a person with dementia are exposed to extensive demands and stresses [
1‐
4]. The stress experienced by carers is particularly high if they do not receive support in caring for their relative with dementia [
5]. It is often difficult for family carers to take advantage of assistance because relief services such as day care, outpatient care or individual counselling are not available or are inadequate and/or knowledge about these offers and their financing (e.g., through care legislation) is lacking [
6]. Care and nursing are time-consuming and bring special challenges to the carer due to dementia symptoms such as memory loss, changes in personality, challenging behaviour, loss of independence, and a high need for care, which pose an increased risk of physical and mental health problems for carers [
7]. Two-thirds of all family carers in Germany, including those caring for a person with a condition other than dementia, experience mental health problems, like symptoms of depression or anxiety [
8]. Medical rehabilitation (rehab) can help support family carers with mental health problems and restore their health. This was shown by a study that evaluated a rehab treatment in northern Germany specifically designed for family carers of people with dementia. However, the health-related and psychosocial effects of this treatment were not sustainable and could no longer be detected after six months [
9]. Thus, aftercare is of particular importance, especially for rehabilitants who care for a relative with dementia. In the medical health services landscape in Germany, there are a large number of established aftercare programmes, such as training and education programmes or counselling services offered by the German Pension Insurance or the health insurance fund, which contain various components to strengthen competence and health. For family carers, however, it is often difficult to organize care for the person with dementia and to spare time for aftercare measures. The Talking Time REHAB project was created to tackle this difficulty in transferring rehab effects to the home environment and showed that carers can be supported in a consolidated manner by telephone-based (and thus location-independent) aftercare groups [
10]. This project idea is also more comprehensively described in the related study protocol [
11]. A meta-analysis shows that telephone -based aftercare can help to increase the sustainability of rehab, especially if there is a high intensity of care [
12]. However, the included studies used predominantly dyadic concepts. In contrast, a telephone-based group setting was chosen for the aftercare of family carers in Talking Time REHAB, and the aftercare was conducted in the context of a telephone conference. Groups can prevent social isolation and present the possibility of exchange and learning from each other, which is also used in theme-centred interaction (TCI) according to Ruth Cohn [
13]. Therefore, TCI was used as the conceptual background for the aftercare groups. Formally, the aftercare groups were based on telephone-based groups in conjunction with the home visiting programme for family carers of people with dementia developed in the USA (Resources for Enhancing Alzheimer`s Caregiver Health II, REACH II) as an intervention component for social support [
14,
15].