Validation of the STOP-bang tool and prevalence of undiagnosed obstructive sleep apnoea in an irish tertiary cardiology outpatient setting.

BACKGROUND

Obstructive sleep apnoea (OSA) is prevalent among patients with cardiovascular disease and is associated with adverse outcomes. The STOP-Bang questionnaire is a validated screening tool for OSA.

AIMS: This study aimed to estimate prevalence of undiagnosed OSA in a general cardiology outpatient population, and validate the tool by correlating results with sleep studies.

METHODS

STOP-Bang analyses were conducted on 250 sequential patients in a general cardiology clinic, with informed consent for sleep studies. 50 patients were selected from for sleep studies.

RESULTS

Among the 245 eligible participants, 118 (48.1%) were classified as high risk for moderate-severe OSA. Of patients deemed "high-risk" on the questionnaire (score ≥ 3), this score had a sensitivity of 68% and a specificity of 80%, a positive predictive value (PPV) of 77.3% and a negative predictive value (NPV) of 71.4% for detecting moderate to severe OSA (Apnoea Hypoxia Index (AHI) ≥ 15). A STOP-Bang score of ≥ 5 was identified as the optimal cut-off for detecting moderate to severe OSA in this population, providing a favourable balance of high specificity (92.9%) and PPV (88.9%), while maintaining reasonable sensitivity (72.7%). The area under the receiver operating characteristic (ROC) curve for predicting AHI was 0.79 (95% confidence interval [CI] 0.62-0.92).

CONCLUSIONS

This study highlights the significant prevalence of undiagnosed OSA within the general cardiology population, emphasising the need for efficient and reliable screening methods. The STOP-Bang questionnaire cut off of ≥ 5 is a useful screening tool with high specificity for OSA. Routine screening of all referrals to cardiology clinics would dramatically reduce the rates of undiagnosed OSA and improve mortality.