Severe Aplastic Anemia: A Systematic Literature Review on Costs of Illness

Abstract

Introduction: Aplastic anemia (AA) is a rare and potentially life-threatening disorder of inherited or acquired bone marrow failure, progressively leading to pancytopenia. AA has an annual incidence estimated at 2 cases per million in Europe and US/Canada, which tends to be significantly higher in East Asia. Severe clinical presentations of the disease constitute hematological emergencies and incur a substantial economic burden to health systems, patients, and caregivers. Our systematic literature review (SLR) of costs of illness of severe AA (SAA) globally describes the economic implications of the disease. Methods: This SLR was conducted using MEDLINE (through PubMed), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, Web of Science, National Health Service Economic Evaluation Database, and the National Health Service Health Technology Assessment Database. The objective was to identify records of studies published from inception up until 31 May 2022, reporting estimates of direct, indirect, and total costs of illness of SAA in any currency. No eligibility criteria concerning study type, language, geography, or time limits were employed. Retrieved records were screened for eligibility by two reviewers independently and any disagreements were resolved by a third investigator. Extracted data were then quality checked. Costs were adjusted and converted to 2021 US dollars. Results: The search identified 768 publications, of which 28 were selected for full-text review and 11 were included in the final analysis. Four studies were from the USA and one each from Sweden, Germany, France, South Africa, Mexico, Brazil, and China. Five studies presented retrospective analyses of real-world data, five reported cost-effectiveness treatment data and one estimated the budget impact of treatment for SAA. Two studies presented cost estimates by age strata and one evaluated SAA treatment-related costs in children. The mean per patient monthly direct cost ranged from $430 (immunosuppressive therapy (IST), China) to $40,107 (IST, USA). The mean direct cost in children treated for SAA amounted to $18,029 and for patients ≤21 years of age the total cost of illness was estimated between $979 and $23,351 per patient. SAA-related costs were lower among older patients. None of the studies reported informal care or indirect costs. Overall, the cost key driver were prescription medications. However, the associated costs to prescription medicines were counterbalanced by reduced hospitalizations, outpatient costs and rescue medication used. Conclusions: To the best of our knowledge, no study has systematically reviewed the literature for estimates pertaining to the economic impact of SAA. Available evidence on the costs of illness of the disease is extremely limited and considerably heterogenous in terms of geographical territories. Further research is needed to identify excess costs and cost variations so as to improve disease management practices in purpose of attaining better patient outcomes and disease prognosis at lower cost.