Face and content validity, acceptability, feasibility, and implementability of a novel outcome measure for children with life-limiting or life-threatening illness in three sub-Saharan African countries

Background: The Children's Palliative Care Outcome Scale (C-POS) is the first measure developed for children with life-limiting and -threatening illness. It is essential to determine whether the measure addresses what matters to children, and if they can comprehend and respond to its items. Aim: To determine the face and content validity, comprehensiveness, comprehensibility, acceptability and feasibility, and implementability of the C-POS. Design: Mixed methods (1) Content validation: mapping C-POS items onto an evidence-based framework from prior evidence; (2) Comprehensiveness, comprehensibility, acceptability feasibility, and implementability: qualitative in-depth and cognitive interviews with a purposive sample of children and young people (n = 6), family caregivers (n = 16), and health workers (n = 12) recruited from tertiary facilities in Kenya, South Africa, and Uganda. Results: (1) C-POS content mapped on to palliative care domains for (a) children (i.e. physical (e.g. symptoms), social (e.g. play/socialize), psychological (e.g. happy)) and (b) families (i.e. psychological (e.g. worry), social (e.g. information), and help and advice). (2) C-POS items were well understood by children and their caregivers, acceptable, and relevant. Completion time was a median of 10 min, patients/caregivers and health workers reported that using the C-POS improved their communication with children and young people. Methodological and content issues included: (i) conceptual gap in the spiritual/existential domain; (ii) further consideration of developmental, age-appropriate items in the social and psychological domains, and (iii) linguistic complexity and difficulty in proxy rating. Conclusion: C-POS items capture the core symptoms and concerns that matter to children and their families. C-POS is feasible, comprehensible, and acceptable for use in clinical settings; areas for further development and improvement are identified.