Study selection
Three authors independently reviewed studies from six databases,
resolving conflicts with a 4th author. The PICO
(Population, Intervention, Comparison, Outcome) framework was used to
evaluate titles and abstracts of initially selected studies. A narrowed
number of studies that met eligibility criteria were selected for
full-text review. The same process was used for data extraction, quality
assessment, and manual search. Study consolidations were done manually
using Microsoft Excel.