<unk> s are a type of<unk>  that uses repeatable analytical methods to collect secondary data and analyse it.<unk> s are a type of evidence synthesis which formulate research questions that are broad or narrow in scope, and identify and synthesize data that directly relate to the<unk>  question. While some people might associate<unk> ' with 'meta-analysis', there are multiple kinds of<unk>  which can be defined as<unk> ' which do not involve a meta-analysis. Some<unk> s critically appraise research studies, and synthesize findings qualitatively or quantitatively.<unk> s are often designed to provide an exhaustive summary of current evidence relevant to a research question. For example,<unk> s of randomized controlled trials are an important way of informing evidence-based medicine, and a<unk>  of existing studies is often quicker and cheaper than embarking on a new study. While<unk> s are often applied in the biomedical or healthcare context, they can be used in other areas where an assessment of a precisely defined subject would be helpful.<unk> s may examine clinical tests, public health interventions, environmental interventions, social interventions, adverse effects, qualitative evidence syntheses, methodological<unk> s, policy<unk> s, and economic evaluations. An understanding of<unk> s and how to implement them in practice is highly recommended for professionals involved in the delivery of health care, public health and public policy.
Systematic review
Natural history study
Subgroup analysis
Platform trial
Clinical study report
Electronic patient-reported outcome
Cohort study
Intersalt study