Obstructive sleep apnea (OSA) screening and risk of postoperative complications in adult surgical patients: differences between the STOP-Bang and Step-2 scoring strategy

PURPOSE: Obstructive sleep apnea (OSA) is associated with an increased risk of postoperative complications. However, data on the relationship between previously undiagnosed high-risk patients and postoperative outcomes remain limited. The study aimed to evaluate the association between OSA risk-assessed using the STOP-Bang score (SBS) and the Step-2 scoring strategy - and the incidence of postoperative complications as well as prolonged hospital length of stay. METHODS: A total of 4,292 adult patients undergoing elective, non-cardiac surgery between 2015 to 2016 were included. All patients underwent preoperative assessment for OSA risk using the STOP-Bang score questionnaire and the Step-2 algorithm. Patients were stratified into low-risk (SBS 0-2) and high-risk (HR) groups, defined as either (SBS 5-8 (S1HR) or Step-2 high-risk (S2HR). The primary outcome was the occurrence of major postoperative complications. Secondary outcomes included prolonged hospital length of stay. RESULTS: Patients classified as high-risk for OSA exhibited a significant increased risk of major postoperative complications compared with the low-risk group (odds ratio [OR]: 1.65 (95% CI 1.09-2.48); S2HR vs. low-risk: OR 2.17 (95% CI 1.57-3.01). No significant difference in complications risk was observed between the two high-risk stratification methods (OR 0.96 (95% CI 0.64-1.33; P = 0.8). Similarly, high-risk patients were more likely to experience prolonged hospital stays (OR 1.34, 95% CI 1.02-1.76; P = 0.003 for S1HR; OR 1.54, 95% CI 1.29-1.87; P = 0.01 for S2HR), with no significant difference between the high-risk groups (OR 1.03, 95% CI 0.79-1.34; P = 0.7). CONCLUSIONS: A high-risk for OSA, as identified by either the STOP-Bang or Step-2 assessment tools, is independently associated with an increased risk of postoperative complications and prolonged hospital length of stay. Both screening strategies demonstrated comparable predictive performance. These findings underscore the value of structured preoperative screening in identifying patients with a high likelihood of previously undiagnosed OSA and in guiding perioperative risk stratification and postoperative management.