Evaluation of a Pre-Operative Clinic's Sleep Apnea Screening

Background This quality improvement (QI) project aimed to evaluate the process and outcomes of utilizing the STOP-BANG questionnaire (SBQ) to screen patients for sleep apnea in a pre-operative clinic. Studies outside the United States show that there is a greater risk for obstructive sleep apnea (OSA) among Asian ethnicity compared to Whites; thus, this project also aimed to describe the SBQ scores of a subset of Asian Americans not referred for a sleep study and determine the number of potential referrals if the body mass index (BMI) threshold in their SBQ scores is modified. Methods A retrospective medical records review identified patients referred for a sleep study at the pre-operative clinic, described the sleep study outcome results, and identified gaps in the referral process that future QI projects can address. The records review also identified SBQ scores of Asian Americans not referred for a sleep study. Their scores were recalculated using a lower BMI threshold to determine the proportion of those who could have been referred. Results There were 72,413 patient encounters at the pre-operative clinics from January 2019 to December 2021; 279 patients were referred for a sleep study. Only 103 (36.92%) completed the test. There were 34 (33.01%) confirmed to have severe sleep apnea, 28 (27.18%) with moderate sleep apnea, 29 (28.16%) with mild sleep apnea, and 12 (11.65%) with no sleep apnea. Of the 176 (63.08%) sleep study referrals not completed, the most common reasons for non-completion were issues with timely scheduling, educating patients to encourage study completion, and handling insurance denials. The mean BMI of the 1,560 Asian Americans not referred for a sleep study was 25.42 kg/m2, and only 2.31% had a BMI > 35 kg/m2. Among the 162 Asian Americans with a history of sleep apnea, only 14.81% had a BMI > 35 kg/m2. Adjusting the BMI threshold of SBQ increased the number of Asian Americans who could be referred for a sleep study by 1.35% and 2.12% if using a cut-off of > 30 kg/m2 and > 28 kg/m2, respectively. Conclusions Screening of OSA using the SBQ in a pre-operative clinic effectively identified patients at high risk for sleep apnea. The low completion rate of sleep study referrals shows a gap in the referral process that requires improvement. Asian Americans with sleep apnea have lower BMIs. Attention to BMI thresholds would increase the identification of sleep apnea in this vulnerable population.