Table 2 Overview of the number of articles identified by different searches and with or without complete abstract reporting

Number of articles in study population (based on broad search)

28

23

16

Number of articles retrieved by specific search*

12

11

4

Number of articles with complete abstract reporting*

12

11

4

Number of articles with complete abstract reporting (excluding database-added keywords)

9

8

4

Number of articles identified only on database-specific keywords

3

3

0