One of the barriers of integrating ethics in Health Technology Assessment (HTA) relates to the social role of HTA (1). The aim of this study is to provide a better understanding of the way by which law circumscribes the social role of HTA. Our hypothesis: HTA's social role is embedded within a mixed governance based on hard law and soft law.

Three HTA agencies were conveniently selected for our study: Haute Autorité de santé (HAS) (France), National Institute for Health and Care Excellence (NICE) (United Kingdom) and Institut national d'excellence en santé et en services sociaux (INESSS) (Québec, Canada). Our analysis of the legal, administrative and procedural documents relating to the existence and assessment processes of these three agencies is guided by the following criteria:

1. 1. The normative strength of the documents (categories of hard law or soft law) (2)

2. 2. The definition of the agencies’ social role (1)

3. 3. The integration of ethics in the agencies’ mandate.

Hard law contributes to establish a general mandate and some legal legitimacy for these agencies. Soft law, grounded in the HTA producers' practices, plays a major role in the legal governance of HTA. Our results demonstrate that these agencies existing practices seem to circumscribe their social role further than their constitutive laws. In this context, social actors become responsible to define, structure and operationalize the implementation of HTA.

In addition, the legal framework (hard law) through which HTA unfolds does not clearly support its structural and social role. Despite existing legal frameworks, the normative legitimacy of HTA is not entirely established, as it depends on soft law. Taken altogether, this maintains a persisting conceptual vagueness in HTA governance.

The social role of HTA should be defined either through modifying existing legislations (hard law) or through harmonization of the agencies internal policies and regulations (soft law). Such legal initiatives would help clarify the aims of HTA evaluations: assessments (scientific) or appraisal (value-laden), and therefore give a clearer indication on how best to integrate ethics in HTA.