2.4 . Quality Assessment
The quality of included studies was assessed using “ Quality Assessment of
Controlled Intervention Studies ” 19 developed by The National Heart , Lung , and Blood Institute ( NHLBI ) and Research Triangle Institute International Jointly . It includes 14 criteria that need to be assessed , which refer to the internal validity of each of the included studies based on their methodology . All of the criteria were scored with either yes , no , Cannot Determine ( CD ), or Not Applicable ( NA ). A “ yes ” was given one point , whereas a “ no ” was given a score of 0 .
No standard for a good , moderate , or poor study was given . Hence , a study obtaining a score of 11 / 14 or higher was defined as a good quality study , meanwhile studies receiving a score of 7 / 14 or less were defined as poor studies . A score between 7 and 11 out of 14 was defined as moderate .
Two reviewers ( RA , OEY ) independently analyzed the included studies based on the quality assessment criteria . If the ratings differed , the articles were discussed until a common consensus was reached .
3 . Results 3.1 . Research Findings and Study Selection
The search terms were applied to all of the 6 search engines and databases mentioned earlier . Titles and abstracts were screened and relevant titles were selected . After removal of duplicates , a total of 61 studies were obtained from the database search . Initial screening of abstracts against eligibility criteria excluded 41 studies . A further 14 trials were excluded after reading full text articles as they did not have a viable study design based on preset inclusion and exclusion criteria . The comprehensive data on the study selection process can be seen in Figure 1 .
The six clinical trials selected in this systematic review were conducted by Dayan , et al . ( 2013 ), 20 HSS , et al . ( 2013 ), 21 Lanata , et al ( 2012 ), 22 Sabchareon , et al ( 2012 ), 23 Villar , et al ( 2013 ), 24 and Leo , et al ( 2012 ). 25