2.3 Study selection and quality assessment:
Two authors () individually reviewed the titles and abstracts of the
literature extracted from database search. Each author filtered the
studies based on the predetermined eligibility criteria. Any conflict
was resolved through discussion and an earlier agreement that a third
author (AK) would evaluate the differences in opinion. The
Newcastle-Ottawa Scale (NOS) was utilized to assess the risk of bias of
the included studies. Two authors (KR, RKP) independently performed and
reported the Newcastle-Ottawa Scale (NOS), differences resolved by
discussion and after consultation with the third author (AK). The
studies were categorized as: low bias risk (8-9 points), moderate bias
risk (5-7 points), and high bias risk (0-4 points).