Holistic burden of illness in patients with endogenous Cushing's syndrome: A systematic literature review

Objective: The objective of this systematic literature review (SLR) was to summarize the latest studies evaluating the burden of illness in endogenous Cushing's syndrome (CS), including the impact of CS on overall and domain-specific health-related quality of life (HRQoL) and the economic burden of CS to provide a holistic understanding of disease and treatment burden. Methods: An SLR was conducted in PubMed, MEDLINE and Embase using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to identify peer-reviewed manuscripts and conference abstracts published in English from 2015 to December 4, 2020. Results: Forty-five publications were eligible for inclusion; data were extracted from 37 primary studies while 8 SLRs were included for reference only. Thirty-one studies reported HRQoL using validated patient reported outcome (PRO) measures in pre- or post-surgery, radiotherapy and pharmacotherapy patients. Overall, this SLR found that patients with CS have worse outcomes relative to healthy populations across specific dimensions, such as depression, despite an improvement in HRQoL post-treatment. These findings reveal that CS symptoms are not fully resolved by the existing care paradigm. Few studies report on the economic burden of CS and currently available data indicate a high direct healthcare system cost burden. Conclusions: Patients with CS experience a significant, complex and multifactorial HRQoL burden. Symptom-specific burden studies are sparse in the literature and the understanding of long-term CS symptomatic burden and economic burden is limited. This review intends to provide an updated reference for clinicians, payers and other stakeholders on the burden of CS as reported in published literature and to encourage further research in this area.