Development of CaReScreen, a Digital Health Tool for Assessing Late Effects and Cancer Rehabilitation Needs in Cancer Survivors: Protocol for a Qualitative Development and Formative Design Study

Background: Due to advances in cancer diagnostics and treatments, life expectancy after cancer and the number of cancer survivors are increasing. Symptoms and late effects frequently occur in cancer survivors, with a negative impact on functioning and participation in society. Digital health tools might be helpful to systematically assess symptom burden of late effects and rehabilitation needs. Objective: This paper describes the objectives, design, and current status of the Cancer Rehabilitation Screening (CaReScreen) project. The aims are (1) to report the completed development phase of the digital health tool CaReScreen, comprising the exploratory work, the establishment of the interdisciplinary team, the selection of the assessment instrument, and the development of the initial prototype, and (2) to define the objectives, design, and timelines of the ongoing validation of the scoring manual and of the planned large-scale feasibility study. Methods: Development followed an iterative, qualitative, and participatory design approach guided by established frameworks for digital health development. It was informed by exploratory qualitative work comprising 40 interviews (9 group and 31 individual) involving 72 informants across Norway, which identified systematic assessment of late effects and navigation of rehabilitation services as the primary unmet needs in cancer survivorship follow-up. A 105-item patient-reported outcome measure (European Organization for Research and Treatment of Cancer [EORTC] QLQ-SURV100, supplemented with 5 EORTC QLQ-C30 items) was selected as the main assessment instrument. This paper reports the completed development phase; the ongoing validation study and the planned feasibility study are described in terms of objectives, design, and timelines, but their results are not reported here. Results: An initial prototype was developed with health care professionals and cancer survivors as intended end users. It consists of a digital report that identifies and graphically visualizes a panoramic view of multidimensional needs, based on a traffic light scoring system: green indicates low symptom burden and high functioning, yellow moderate symptom burden and moderate functioning, and red high symptom burden and low functioning. The project is funded for the period 2022 to 2028. The development phase is completed, as well as early prototype usability and usefulness testing. Validation of the scoring manual is ongoing, with 800 participants included to date and reporting expected in spring 2027. A large-scale feasibility study is planned to commence in 2027. Conclusions: The CaReScreen interdisciplinary team has developed an initial digital health tool prototype with the main aim of enabling systematic assessment of late effects, functioning, and unmet rehabilitation needs in cancer survivors. The prototype now proceeds to validation and feasibility testing, which will determine its clinical utility and support regulatory approval under the European Medical Device Regulation.