[Diagnostic accuracy of STOP-Bang questionnaire on moderate sleep apnoea in primary care]

We aimed to compare the diagnostic utility of the STOP-Bang questionnaire for moderate apnoea against the gold standard (type I polysomnography) in a primary care setting.

Study of diagnostic utility in primary care. Estimated sample: 85 cases and 85 healthy controls. In convenience sampling, 203 patients were recruited by their physicians at six health centres. Twenty-five were excluded, and 57 women and 121 men, of whom 74 had apnoea-hypopnoea index (AHI) ≥15, were analyzed. STOP-Bang was validated by comparing scores in the same patient with the apnoea-hypopnoea index observed in polysomnography, as a gold standard. Sample size, ROC curve analysis and optimal cut-off points were identified with the easyROC, pROC, and OptimalCutpoints packages.

The area under the curve in moderate apnoea (AHI ≥15) of the STOP-Bang was 0.777 (0.667-0.808), with optimal cut-off points different by sex (4 in women and 6 in men). In the cross-validation with k=10, the area under the curve for the STOP-Bang was 0.678.

The STOP-Bang presents a diagnostic moderate utility for AHI≥15, but superior to other scales, in a community population. Its performance is more appropriate in women.