Cluster | Reviews included | Range of primary studies included | Total no of primary studies included | No of primary studies appearing in more than one review | Primary studies publication dates |
Discharge intervention reviews | 12 13 15–17* | 5–14 | 25 | 9 | 1996–2013 |
Staff-focused reviews | 11 18–21* | 2–11 | 15 | 9 | 1996–2015 |
Population-focused reviews | 22 23* | 12–15 | 27 | 4 | 1994–2011 |
Intervention component reviews | 24–26* | 15–20 | 38 | 13 | 1994–2018 |
*A subset of papers in the following reviews were reported.12 17 18 23 24