Measurement of treatment burden in cystic fibrosis: A systematic review

•This is the first systematic review of measures to quantify treatment burden in people with CF.•Both subjective and objective measures are used to quantify treatment burden.•No single measure captures all dimensions of treatment burden.•Deploying complementary subjective and objective measures facilitates capture of a broader array of treatment burden dimensions.•Ultimately it may be necessary to revisit the concept of treatment burden in the era of highly effective CFTR modulators. Cystic fibrosis (CF) is a chronic condition that requires complex and long-term treatments. While substantial research has explored treatment burden associated with CF; its impact remains complex to quantify. This review aims to identify the different methods used in the literature to measure treatment burden in people with CF (pwCF). Five databases were searched for interventional and observational studies that focused primarily on treatment burden. The studies were presented using narrative synthesis structured around the perspective of treatment burden (subjective vs. objective). This review synthesised 17 articles, which utilised subjective and objective measures separately or collectively. Twelve studies used subjective treatment burden measures (CF-specific and generic scales), while 14 studies used objective measures (treatment time, volume and complexity, and cost). Eight studies investigated treatment burden reported by proxy on behalf of children with CF. The most used measures were treatment time (9/17) and CF questionnaire-revised (CFQ-R) treatment burden subscale (6/17). Older age and lower lung function were associated with greater burden, treatment time, and complexity. Caregivers/parents reported worse treatment burden compared to children with CF (6-13 y/o) when completing the same measure. No single measure used in the reviewed studies fully the multidimensional nature of treatment burden and summarised it in a single score. Given the rapidly evolving landscape of CF care a pragmatic approach to capture a broader array of treatment burden dimensions may be to routinely complement subjective measures with objective measures.