Systematic reviews are powerful tools for answering focused research questions. Focused questions that are specified sufficiently and contain all necessary elements similar to typical experimental studies are suitable questions. These are known as closed-framed questions. In contrast broad questions, also known as open-framed, are in fact overarching questions containing multiple closed-frame questions. [1] They cannot be addressed by using the systematic review method.
Scoping studies can be used to breakdown broad research questions to focused ones. You can learn more about the procedure in the scoping study section of the supplementary contents section.
Closed framed questions |
What is the prevalence or incidence of disease O in population P? |
How much of O occurs in population (foodstuff, environment, etc.) P |
How much of O does population P consume? |
Is there a dose-response relationship between intervention I (at different does C) and outcome O in population P? |
Is E a risk factor for O in population P? |
Is E the cause of O in population P? |
Open framed questions |
What is the best intervention to reduce effect O in population P? (determine I, C) |
What tests are available to determine condition T? (determine P, I) |
Does disease O occur in species P? (yes/no question not amenable to SR) |
P) Population(s) (l) lntervention(s) or (E) Exposure(s) (l) lndex test(s) (C) Comparator(s)
(T) Target condition(s) (O) Outcome(s)
Source: EFSA Guidance for Those Carrying out Systematic Reviews European Food Safety Authority. (2010). Application of systematic review methodology to food and feed safety assessments to support decision making. EFSA journal, 8(6), 1637.