Introduction: The recently created Health Technology Assessment System (SiNATS) in Portugal will
allow the reassessment of health technologies in a clinical practice context. This position paper intends to list and briefly describe the numerous challenges and limitations that may influence the premises and the Outcomes of the health technology reassessments and therefore its own purpose. This paper reflects the position adopted by the ISPOR Portugal Regional Chapter (International Society for Pharmacoeconomics and Outcomes Research – ISPOR Portugal) regarding this subject.

Methods: A group of members of ISPOR Portugal reviewed the literature available, namely documents of international workgroups that have previously focused on similar matters, and conducted a critical analysis on the challenges faced by health technologies reassessment within the national context. A final revision of the paper was requested to all members of the ISPOR Portugal Regional Chapter.

Results: Several limitations that may potentially compromise the reassessment of health technologies have been identified and thoroughly described, namely those with regard to the intervention itself (i.e. the health technology), the study population, the selection of the comparator and the Health Outcomes to consider in this type of analysis. The relevance of the information sources on which the investigation of comparative effectiveness may rely upon (at least to some extent) as well as the limitations and flaws inherent to it (i.e. bias and confounding factors) were also highlighted.

Conclusions: A health technology reassessment system must be subject to an a priori analysis regarding its potentialities and limitations. In this paper these issues are addressed while taking SiNATS’s goals as reference points. Nevertheless, it is necessary to give continuity to this work, particularly through the creation of workgroups whose purpose is to study and analyse with greater detail the matters mentioned herein. Such work may, in fact, prove to be crucial for a successful implementation of a reassessment system that makes fair and efficient decisions on the funding of health technologies in Portugal.