“…However, none of them mentioned the power of the study. In 10 out of 14 studies, confounding variables were quantified and statistically adjusted using multivariate logistic regression [ 21 , 23 , 24 , 25 , 26 , 27 , 28 , 30 , 31 , 32 ]. To conclude, nine studies were rated good quality [ 21 , 23 , 24 , 25 , 27 , 28 , 30 , 32 , 33 ], two were rated fair quality [ 26 , 31 ], and the remaining three were rated poor quality.…”