Expanding the Catalog of Patient and Caregiver Out-of-Pocket Costs: A Systematic Literature Review.

Out-of-pocket (OOP) health care expenditures in the United States have increased significantly in the past 5 decades. Most research on OOP costs focuses on expenditures related to insurance and cost-sharing payments or on costs related to specific conditions or settings, and does not capture the full picture of the financial burden on patients and unpaid caregivers. The aim for this systematic literature review was to identify and categorize the multitude of OOP costs to patients and unpaid caregivers, aid in the development of a more comprehensive catalog of OOP costs, and highlight potential gaps in the literature. The authors found that OOP costs are multifarious and underestimated. Across 817 included articles, the authors identified 31 subcategories of OOP costs related to direct medical (eg, insurance premiums), direct nonmedical (eg, transportation), and indirect spending (eg, absenteeism). In addition, 42% of articles studied an expenditure that the authors did not label as "OOP." A holistic and comprehensive catalog of OOP costs can inform future research, interventions, and policies related to financial barriers to health care in the United States to ensure the full range of costs for patients and unpaid caregivers are acknowledged and addressed.