Selection of indirect treatment comparisons for health technology assessments: a practical guide for health economics and outcomes research scientists and clinicians

Abstract

Background Health technology assessment (HTA) bodies evaluate the clinical and economic values of health interventions to inform healthcare decision-making. They face the challenge of lacking head-to-head randomised clinical trial data against the standard of care. Indirect treatment comparison (ITC) methods are often used and accepted by HTA bodies worldwide, but there are numerous options with various and inconsistent terminologies. The selection and application of ITC methods are complex from methodological and clinical perspectives. Objectives This article (1) provides a comprehensive overview of ITC methods by clarifying used terminologies, including fundamental assumptions, frameworks, strengths, limitations, applications and specific considerations; (2) examines recent ITC guidelines with recommendations or preferences from major HTA bodies and (3) guides health economics and outcomes research (HEOR) scientists and clinicians in the strategic selection of ITC methods with case examples. Methods The authors conducted a rapid review to identify the literature related to ITC methods and ITC-relevant HTA guidelines in various databases between 2009 and April 2024. Conclusions Comprehensive knowledge of the ITC methods landscape and the evolving ITC-relevant HTA guidelines are essential for ITC methods selection. Effective communication/collaboration between HEOR scientists and clinicians ensures that the selection and justification of ITC methods are robust for HTA submissions.