DIAGNOSTIC-ACCURACY OF A PORTABLE RECORDING DEVICE (MESAM-IV) IN SUSPECTED OBSTRUCTIVE SLEEP-APNEA

This study evaluated the accuracy of a portable recording device (MESA M IV) in identifying obstructive sleep apnoea (OSA). The MESAM IV syst em measures arterial oxygen saturation (Sa,O-2), heart rate, snoring s ounds and body position, and allows both automatic and manual scoring of the recordings, Nocturnal polysomnography and MESAM IV recordings w ere performed simultaneously in 150 patients with suspected OSA, and w ere analysed blindly by a different observer. Patients with an apnoea- hypopnoea index (AHI) greater than or equal to 10 were diagnosed as ha ving OSA, In the evaluation of the discriminatory ability of MESAM IV scores, the cut-off point was set to minimize first the exclusion of t ruly diseased patients (i.e. false-negative interpretations), and then the confirmation of nondiseased subjects (i.e. false-positives). When used as an exclusion test, the portable device reached a sensitivity of 0.98 and a specificity of 0.78; as a confirmation test, these value s were 0.69 and 0.97, respectively, These results were achieved with m anual scoring, which was superior to automatic scoring, Manual scoring was also better than automatic scoring when OSA was defined according to other threshold values (greater than or equal to, 15 and 20) for t he AHI. The combination of MESAM IV manual scores could reduce the nee d for diagnostic polysomnography in three quarters of the patients cli nically suspected of having obstructive sleep apnoea, substantially re ducing costs associated with diagnostic procedures.