Health Technology Assessment (HTA) is a comprehensive form of policy research that provides
information on the consequences of the application of health technology. It is used primarily to guide health
care resource allocation decisions. In Thailand, there is increasing impetus to use HTA information to allow
more explicit and transparent health care priority setting. A previous study indicated that serious attention
needed to be given to the quality of reporting and the use of information in the analyses. These problems could
be reduced by setting up standard guidelines for conducting HTA to stimulate the provision of standardized,
reliable and good quality information for policy makers. Nevertheless, Thailand has not yet set up such
guidelines. This may lead to low quality evaluations. Therefore, the objective of this article was to describe the
rationale for guideline development, supporting principles, guideline development process, sources of
information, and future challenges for HTA.

Keywords: Health technology assessment, Rationale, Guideline development