Literature search and study characteristics
Literature search of various databases yielded a total of 360 citations which were imported on a citation manager. Of these 107 duplicate articles were removed and other 178 articles were removed after initial title and abstract screening due to various reasons (Figure 1). Seventy-five articles were selected for full text review. For final analysis 50 articles were included and remaining 25 articles were excluded due to non randomized nature of studies.