“…Due to the heterogeneity of published studies, a meta-analysis was not appropriate, so the results were qualitatively described. Based on the OCEBM 2011 Levels of Evidence table 58 the majority (76.5%) were level 4 (20 case report 8,16,18,19,21,23,[27][28][29][30]36,37,39,[42][43][44]47,49,51,53 , 10 case series 17,20,22,26,32,34,35,41,48,59 , and 9 historical cohort [9][10][11]13,15,24,[55][56][57] ), whereas the remainder 12 papers (23.5%) were of level 3 (6 cohort 12,25,33,40,46,50 and 6 cross sectional studies) 14,31,38,45,…”