EUnetHTA
In the context of adapting HTA reports, a reliable report is one that a potential user can trust and rely on: they can trust that what it says is true. If so, they may be adopted or considered for adaptation for another setting. One way of assessing reliability in a standardized way is through the use of quality checklists, such as those that are included in the EUnetHTA Toolkit.
Note however that reliability is a tricky word and should be used with caution. Although reliability is widely used in HTA as above, in other situations, it refers to repeatability, which leads to the common observation that a repeatable test is not necessarily a valid one. However, in the case of HTA, reliability can also be used to mean “how far something can be relied on or trusted”, which is very close to (internal) validity.
The relevance of an HTA report is determined by how closely the policy and research question(s) in the report match the research questions that are of interest to the user. Relevance is therefore a relative or subjective matter: it is the relevance for the user and not a general ‘standard’ relevance. Relevance therefore depends on the setting, the knowledge of the adapting person and the policy question.
A report might be very relevant even if it is not reliable – and vice versa.