Table 1.

Types of questions about healthcare interventions that overviews can examine^a

1	Different interventions for the same condition or population.
2	Different approaches to the application of the same intervention for the same condition or population.
3	Same intervention for different conditions or populations.
4	Adverse effects of an intervention for one or more conditions or populations.
5	The same intervention for the same condition or population, where different outcomes or time points are addressed.

^aFrom Pollock et al. 2019 Cochrane Handbook chapter on overviews of reviews [draft] [1]