3.1 Guideline Selection
After screening for relevance in databases, 471 records were initially identified and 43 records were excluded for duplicates. After screening the title and abstract of records, 375 records were excluded because they were about animals, sanitary technical guidance or irrelevant. 53 remaining records were retrieved for full text and 33 records were excluded because they were guidance documents on health work. Finally, 20 CPGs were selected (Figure 1 ). Table 1 presented the basic information of the included guidelines,