What we need to know about uncertainty in illness among people with primary malignant brain tumours: A mixed-methods systematic review

Aims and objectives: To identify the characteristics of uncertainty in illness (UI) among people with primary malignant brain tumours (PMBT). Background: High recurrence rates and complex symptoms cause uncertainty in people with PMBT. Given the characteristics of PMBT, reviewing UI among people with PMBT will benefit future research and clinical intervention development. Design: A mixed-methods systematic review. Methods: We performed a mixed-methods systematic review (PubMed, CINAHL, Embase, PsycINFO, Scopus and Cochrane Library), including studies on UI among people with PMBT, searched from the databases' inception to the search date. The initial search was conducted in July 2021, with an additional search in March 2022. The major search terms were PMBT and UI, and no limitations were placed on the study design. The Cochrane tool was used to evaluate the risk of bias in randomised controlled trials, and JBI checklists were used to evaluate quasi-experimental studies, survey methodology studies and a case study. This review was reported using the PRISMA 2020 checklist. Both quantitative and qualitative research data were extracted, analysed and then integrated in three stages of a mixed-methods systematic review. Results: Eleven studies were included. Due to physical, psychological and social risk factors, the UI progression of people with PMBT was complex and ambiguous, although they adapted to the PMBT diagnosis and treatment process. Subsequently, we proposed a model of UI among people with PMBT. Conclusions: UI has multidimensional characteristics, and healthcare providers need to consider these aspects for people with PMBT. Relevance to clinical practice: The proposed model provides directions for nursing practice and future research. Nurses caring for people with PMBT should comprehend their UI and intervene accordingly. Patient or public contribution: This review incorporated data including people with PMBT in hospitals and communities. This analysis contributes to the clinical-to-community nursing transition process for people with PMBT.