ReNaApp: Increasing the long-term effects of oncological rehabilitation through an application after medical rehabilitation (ReNaApp): A quasi-randomized longitudinal study of prospective design

Background: Breast cancer is the most common malignant disease in women. Compared with other cancer types, breast cancer has a higher survival rate. The majority of breast cancer patients are overstrained to implement cancer-specific recommendations relating to changes in health behaviour. Numerous epidemiological studies have shown a positive correlation between physical activity and quality of life as well as the course of disease during and after breast cancer treatment. However, many patients have difficulties integrating physical activity into their everyday lives due to cancer symptoms. To develop physical activity into a daily routine, an aftercare programme for breast cancer patients will be developed. In particular, the programme is structured in terms of the validated concept "Neues Credo". The basic concept is converted into a mobile application. Methods: The study sample includes n = 740 rehabilitants (370 for the intervention group and for the control group) from five different rehab clinics in Northern Germany. The evaluation is as follows: a) Quasi-randomized, prospective longitudinal study (sequential study design). The intervention group receives a mobile application after rehabilitation, and the control group receives treatment as usual. The study evaluation is carried out through a questionnaire at three stages (at the beginning of the rehabilitation, at the end of the rehabilitation, and after 12 months). b) Qualitative analysis of interviews and focus groups in terms of feasibility and acceptance. c) Formative evaluation of the app. Discussion: Above all, the aftercare programme ReNaApp increases the long-term effects of oncological rehabilitation. By documenting physical activity in ReNaApp, rehabilitants become more motivated to engage in physical activity in their everyday lives. Currently, there is no scientifically evaluated app for breast cancer patients in the German language. Thus, ReNaApp ensures an aftercare treatment for breast cancer patients with high-quality performance regardless of their place of residence. By adopting a participatory approach and a user-centred design, ReNaApp corresponds to the demands of the rehabilitants. Trial registration: German Register of Clinical Trials, www.drks.de. Identifier: DRKS00019017; Registered: November 7th, 2019. Date and version identifier: April 17th 2020; vesion 2.