It's a bit more important than that number suggests. For one, 7% of global systematic reviews is not a trivial proportion. But more importantly Cochrane allows

It's a bit more important than that number suggests. For one, 7% of global systematic reviews is not a trivial proportion. But more importantly Cochrane allows for the pre-registration of such reviews, i.e. where the methodology and goals (hypotheses) are stated before the review is conducted. This is probably the most scientifically rigorous method of assessing evidence, and is not performed for most systematic reviews.