The median number of databases searched in 58 reviews was 7 within a range of 4 to 15. Regarding to the English language databases, the most searched was MEDLINE (98%), followed by EMBASE (97%) and CENTRAL (97%). CBM was the most searched Chinese database (78%), the second most used was CNKI (45%) and the third was VIP (24%) ( Table 2 ). All reviews searched at least 2 English databases, while 10 reviews did not search any Chinese database. 41 (71%) reviews searched at least 3 English databases, while only 6 (10%) reviews searched at least 3 Chinese databases (Table 3 ).