HSC Section 3 - Trauma, Critical Care and Sleep Medicine

V ENOUS THROMBOEMBOLISM IN OTOLARYNGOLOGY

FIGURE 1. Inclusion and exclusion flowchart. [Color figure can be viewed at wileyonlinelibrary.com]

330,629, for a total of 618,264 when including all patients from all series. Six of these studies had less than 1000 patients. Demographic information was incomplete for 7 studies with regard to age and 9 studies with regard to sex. Seven series did not specifically report the incidence of DVT, and 6 series did not specifically report PE, although the information for the incidence of VTE was available for all articles. It is important to mention that in the study by Clayburgh et al 8 with the highest incidence of DVT (7.0%), all patients underwent ultrasonography on postoperative day 2, a potential source of bias in the detection rate as many of these may not have been clini- cally evident or relevant. In this study, if only the symp- tomatic patients were to be included, the incidence of DVT would decrease to 3.0%. Anticoagulation protocol

regardless of sample size on this topic in OHNS. The only prospective study (LOE 1b) was conducted by Clay- burgh et al 8 in 2013, however, this was the study with the smallest number of patients ( n 5 100). According to the Oxford Center for Evidence-Based Medicine 2011 LOE, all other studies were either retrospective cohort studies (LOE 2b) or outcomes research studies using databases (LOE 2c). With regard to study outcome follow-up period, 12 studies evaluated VTE outcomes only until dis- charge, whereas all the other studies looked at outcomes up to 30 days after discharge, with the exception of Karagama et al 12 who evaluated outcomes up to 6 weeks after discharge. For the purposes of our analysis, we treated this in the 30 days after discharge or more group. The number of included patients varied from 100 to

HEAD & NECK—DOI 10.1002/HED JUNE 2017

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