“…31,32,35,37,45,46,60,78,[105][106][107] All were simple case-series. Seven studies were in adults 37,45,46,60,[105][106][107] three were in children, 31,32,78 and in one study the age of the study population was not specified. 35 Two of the studies included here fall, strictly, outside the terms of our search strategy, since they were conducted on medical admissions rather than for preoperative assessment.…”