Validation of the POLY-MESAM seven-channel ambulatory recording unit.

STUDY OBJECTIVES To determine the recording capabilities of the POLY-MESAM (PM) unit (MAP; Martinsried, Germany), an American Sleep Disorders Association level III system, and to compare it with simultaneous 12-channel polysomnography in the sleep laboratory. MEASUREMENTS AND RESULTS Fifty-three patients (49 men and 4 women) with obstructive sleep-related breathing disorders of varying severity were included. The apnea-hypopnea indexes (AHIs) obtained using the two methods differed significantly from each other, although the correlation was close. The PM unit produced false-negative results in patients with mild to moderate obstructive sleep apnea (OSA). The sensitivity of the PM unit in detecting patients with an AHI > 10 was 92%, while the specificity was 96.3%. CONCLUSIONS The correlation of AHIs obtained with polysomnography and with the PM unit is close. However, in some cases, the PM may underestimate OSA parameters. The PM unit produces false-negative results in patients with mild to moderate OSA. While inpatient polysomnography remains the "gold standard," the PM unit may provide an inexpensive alternative in some special cases.