Assessment of study quality
The Qualsyst tool (3) was used to assess the quality of each selected
study for meta-analysis. This tool incorporates ten questions (scored
from 0 to 2). Two authors (KM and HI) evaluated the quality of the
selected studies for meta-analysis. The inter-observer agreement for the
quality assessment of the selected studies was performed using the
Weighted Cohen’s kappa (κ) co-efficient.