Characteristics of included Cochrane systematic reviews.

N, number of systematic reviews (unless otherwise indicated).*Based on 358 systematic reviews unless otherwise specified.†38 systematic reviews did not find published studies (n = 22) or include studies that had participants Based on 6,022 studies identified in 358 systematic reviews. Actual number of studies may be less, as some studies may be included in multiple systematic reviews.‡Based on 353 systematic reviews, 5 systematic reviews were unclear or did not specify total number of participants.§Based on 351 systematic reviews, 7 systematic reviews were unclear or did not specify total number of participants.**Based on 394 systematic reviews, two systematic reviews were classified as ‘stable’.††Based on 358 systematic reviews that identified studies. If a systematic review had greater than one category of intervention, it was double counted (n = 15); total interventions evaluated is 376.bBased on all 396 systematic reviews.