Performance of NoSAS score versus Berlin questionnaire for screening obstructive sleep apnoea in patients with resistant hypertension

Obstructive sleep apnoea (OSA) is the main secondary form associated with resistant hypertension (RH), but it is largely underdiagnosed and consequently undertreated in clinical practice. The Berlin questionnaire (BQ) is a useful tool among general population, but seems to not perform well among patients with RH. Recently, NoSAS score was validated in a large population, however, has not been tested in the cardiovascular scenario. Thus, we aimed to compare BQ versus the NoSAS score as screening tools for OSA in RH. In the present study, patients with confirmed diagnosis of RH were invited to perform polysomnography. OSA was diagnosed by an apnoea-hypopnoea index (AHI) ≥15 events/h. BQ and NoSAS were applied in a blinded way. We calculated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the curve (AUC) of the two sleep questionnaires to detect OSA in RH. The frequency of OSA was 64%. The BQ presented a better sensitivity (91 vs. 72%) and higher values of NPV (67 vs. 54%) than NoSAS score. In contrast, the NoSAS score had higher specificity for excluding OSA (58 vs. 33%) and higher PPV (75 vs. 70%). Compared to the BQ, NoSAS score had a better AUC (0.55 vs. 0.64) but these values are in the fail to poor accuracy range. In conclusion, both BQ and NoSAS score had low accuracy for detecting OSA in RH. Considering the high frequency of OSA, objective sleep study may be considered in these patients.