In Response.

Abstract

We would like to thank Twersky et al1 for responding to our recent editorial2 about their original study, by Szeto et al.3 In this study, the authors analyzed data on patients undergoing cancer surgery in the ambulatory setting with a known diagnosis of obstructive sleep apnea (OSA; prevalence of 4.1%) or those who were likely to have OSA (prevalence of 3.5%) based on STOP-BANG (Snoring, Tiredness, Observed apnea, blood Pressure, Body mass index, Age, Neck circumference, and Gender) Questionnaire results. In short, the authors concluded that patients who are moderate or high risk for OSA or those who have been diagnosed with OSA can safely undergo outpatient and advanced ambulatory oncology surgery without a significant increase in complications. As we stated in our editorial, we were surprised to see the authors reporting that only 3.5% of their cancer patient population screened high risk for OSA. We surmised that this might have been due to the fact that a 2-step modified approach to STOP-BANG scoring was used, whereby the investigators initially only asked 4 STOP questions and applied subsequent BANG questions only if patients answered “yes” to 2 or more questions of STOP. This means that if the patient only had 1 positive response on STOP, they would not be considered at risk for OSA. We do thank the authors for clarifying their reasoning why their low reported rate of 3.5% high-risk screens for OSA is unlikely to be due to their aforementioned methodology of administering the STOP-BANG questionnaire. They claim to have performed additional data checks for relevant demographic information. However, we do want to point out that the current literature, including several large recent studies, cites much higher prevalence rates of patients who are high risk for OSA based on screening. For example, a study by Nagappa et al4 found that the probability of severe OSA in the surgical population with a STOP-BANG score of 3 was 15%, and this percentage increased with increasing scores. Others used sleep studies to estimate OSA prevalence, again finding the prevalence of moderate-to-severe sleep-disordered breathing to be several times higher in both men and women. Thus, either differences in methodologies or uniqueness of their patient population may explain the difference between their findings of 3.5% prevalence of being high risk for OSA,3 which is significantly lower than that of several other studies. Richard D. Urman, MD, MBADepartment of Anesthesiology, Perioperative and Pain MedicineHarvard Medical SchoolBrigham and Women’s HospitalBoston, Massachusetts[email protected] Frances Chung, MBBS, FRCPCDepartment of AnesthesiologyUniversity Health NetworkUniversity of TorontoToronto, Ontario, Canada Tong J. Gan, MD, MBA, MHS, FRCADepartment of AnesthesiologyStony Brook UniversityStony Brook, New York