Ant.: retrospective study. Related concept: cohort study.† A study to evaluate the effects of exposure to a given intervention or factor, in which the subjects are divided into groups that are exposed or not exposed to the intervention or factor of interest before the outcomes have occurred. Note: Randomized controlled trials are always prospective, but case-control studies never are. Cohort studies may be prospective or retrospective. † A cohort study may be a prospective study, but a prospective study is not necessarily a cohort study : a cohort study involves a methodology, i.e. comparison, that is not necessarily common to all prospective studies. The qualifier “prospective,” without further details, indicates only the study’s temporal direction.

and • provides information on costs and financial impact. Note 2: The report may optionally discuss organisational considerations. Note 3: A “mini-HTA” may be as rigorous as an HTA report but typically has a restricted scope and so is quicker to produce. Note 4: Related terms include health technology, HTA report, rapid review, level of evidence