A systematic review of the use of burden of treatment theory.

Background: Treatment burden describes the workload undertaken by people with chronic illness and multimorbidity to manage their healthcare demands and the impact on their wellbeing. Burden of Treatment Theory (BOTT) describes the work that people with multimorbidity do to self-manage chronic illness/multimorbidity and the factors that affect capacity (personal and healthcare resources, support network) to meet treatment demands. Here we aim to identify and characterise the different applications of Burden of Treatment Theory in research; to explore the contribution of Burden of Treatment Theory to advancing knowledge and understanding of treatment burden and capacity issues and to identify critiques or limitations of Burden of Treatment Theory in research. Methods: Systematic review of BOTT research published in the English language. Databases searched were Web of Science, Scopus, Medline, CINAHL and medRxiv.org. We also consulted with experts in the field. Two reviewers screened titles, abstracts and papers and undertook data extraction. Quality appraisal was undertaken using adapted CASP checklists for qualitative studies and systematic reviews and a Mixed Studies Review checklist. Results: Thirty papers included: 16 qualitative studies; 5 systematic reviews; 3 protocols; 3 discussion papers, a theory conceptual paper, a realist review and a feasibility trial. Most (n=17) originated in UK, with 3 from Australia and Argentina, 2 from Norway and one each from United States and Malawi. Nine papers mentioned use of BOTT constructs but 21 additionally provided rationale for BOTT use and demonstrated engagement with the theory. Two papers adapted/refined BOTT to the context of their research focus. Twenty-seven studies prospectively outlined use of BOTT, with only 3 applying BOTT retrospectively to report study outputs and 'inform analysis' of findings. Conclusion: BOTT provides a useful conceptual, analytical and sensitising lens in studies focusing on both the characterisation and alleviation of treatment burden through healthcare interventions, and the constructs discussed are stable and applicable across multiple settings. Future research could include use by empirical researchers in contexts needing more adaptation and critical assessment.