Hand-scoring of MESAM 4 recordings is more accurate than automatic analysis in screening for obstructive sleep apnoea

Abstract

The MESAM 4 system, developed to monitor breathing sounds, heart rate, arterial oxygen saturation (SaO2 and body position, was proposed as a screening method for obstructive sleep apnoea (OSA). The aim of the study was to assess the accuracy of hand-scoring versus automatic-scoring in screening far obstructive sleep apnoea. The study population consisted of 56 patients, 51 males, and 5 females, mean age 47±10 yrs, suspected of having obstructive sleep apnoea. Full polysomnography and MESAM 4 recordings were performed simultaneously. The apnoea+hypopnoea index was hand-scored in polysomnography and in MESAM 4. The handscoring in MESAM 4 was based on analysis of breathing sounds, heart rate and SaO2 changes taken together. The automatic-scoring system of MESAM 4 calculated MESAM 4 oxygen desaturation index, heart rate variation index and intermittent snoring index. The diagnosis of obstructive sleep apnoea (apnoea+hypopnoea index ≥10) was established by polysomnography in 37 patients, Sensitivity and specificity of handscored MESAM 4 diagnosis were 100 and 63%, respectively. Sensitivity and specificity of MESAM 4 diagnosis with automatic-scoring were: from oxygen desaturation index 100 and 278; from heart rate variation index 81 and 74% and from intermittent snoring index 92 and 16%, respectively. We suggest that hand-scoring of MESAM 4 is more accurate than automaticscoring in screening for obstructive sleep apnoea.