Avoiding double-counting in pharmacoeconomic studies

Area of Science:

• Health Economics
• Pharmacoeconomics
• Decision Analysis

Background:

• Cost-utility analysis (CUA) is a key method for evaluating pharmaceutical treatments.
• CUAs measure costs in monetary terms and effects as quality-adjusted life years (QALYs).
• QALYs incorporate health-related quality of life using weights from 0 (death) to 1 (perfect health).

Purpose of the Study:

• To outline the potential for double-counting in cost-utility analyses.
• To identify factors influencing the risk of double-counting.
• To propose methods for avoiding double-counting in QALY assessments.

Main Methods:

• The study reviews the principles of cost-utility analysis and QALY construction.
• It analyzes how financing of healthcare and income losses impacts double-counting.
• It examines the effect of question phrasing in quality weight assessments.

Main Results:

• Double-counting can occur when consequences are considered in both cost and QALY calculations.
• The risk of double-counting is influenced by the financing of healthcare costs and income losses.
• The phrasing of questions used to assess quality weights is critical.

Conclusions:

• Double-counting in CUAs can be avoided by instructing respondents to assume full reimbursement for healthcare costs and income losses.
• This approach ensures quality weights reflect only health and leisure changes.
• Other consequences can then be accurately incorporated into the cost estimation.