Health technology assessment (HTA) is a critical part of healthcare decision making in many countries. Changes in Methods and Processes (M&P) of HTA agencies can affect the time and degree of patient access to treatments. Published literature focuses on the different M&P adopted by HTA agencies, rather than on how these have come about over time. Our study investigates key HTA reforms and explores their drivers and interdependencies in a set of HTA agencies in Europe, Asia-Pacific, and North America.

We conducted a targeted literature review on M&P guidelines and subsequent changes to those, for 14 HTA agencies. We supplemented and validated initial findings with 29 semi-structured interviews with country-specific experts. We used analytical tools to create process maps, proactivity and influence networks, and clusters of HTA agencies.

We found that processes leading to M&P reforms follow similar steps across HTA agencies. The three most important drivers to reforms were HTA practice and guidelines in other countries; the healthcare policy, legal, and political context within the agency’s country; and experience of challenges in the assessment by the HTA body itself. International collaborations have the potential to accelerate the evolution of HTA systems and the implementation of reforms.

We identified PBAC (Australia), CDA-AMC (Canada), NICE (England), IQWiG (Germany), and ZIN (the Netherlands) as HTA agencies that are catalysts of HTA reforms as well as internationally influential. International collaborations may represent a useful route to accelerate changes as long as they ensure wide stakeholder engagement at an early stage.