Literature Search
PubMed-Medline, EMBASE, Scopus, Web of Science, Cochrane Library, and www.clinicaltrials.gov were searched. A basic search strategy was developed for PubMed, and modi- fied as needed for other databases; a search strategy was devised for each outcome (Supplemental Table 1, available online). The search time parameters were from inception of each database through March 2014. The language in which studies were written was not used to restrict selection, but only human studies were selected. References from the selected articles, including relevant review papers, were reviewed to identify all relevant studies.