The use of systematic reviews in HTA

Abstract

Basically the Health Technology Assessment (HTA) is based on the scientific method and aims to produce information used in the
field of health policy choices that need to be effective, efficient and safe. For this reason they Systematic Reviews (SR) and Meta-
Analysis (MA) are generally used.
Typically, a single evaluation, even if resulting from an appropriate experimental study, can hardly be considered sufficient to help
in make decisions on a health intervention mainly for statistical considerations (sample size is rather limited). Furthermore, if there
were more primary studies, the results would not completely be in agreement with each other or may be dissimilar as they would be
drawn from different social and economic backgrounds and thus are only partially comparable.
The SR and MA consolidate existing relevant search results in order to resolve any inconsistency or ambiguity between the existing
studies and produce results that are obvious or significant results in individual studies. Often, when one decides to conduct an HTA,
evidence of efficacy are lacking both quantitatively and qualitatively and / or the application contexts are often very dissimilar. Even
in this case, the SR and MA do not generate new data but can produce new knowledge from existing evidence. Also the use of RS and
MA to assess the availability or lack of sufficient evidence (for example on the efficacy of an intervention / treatment) or to indicate
the need to conduct further studies and to generate new evidence pointing out which aspects should be taken into consideration.