RT Journal Article
SR Electronic
T1 Comparison of the polysomnographic apnoea-hypopnea-index with the oxygen desaturation index in patients with obstructive sleep apnoea
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P2236
VO 44
IS Suppl 58
A1 Zayd Tippu
A1 Martino Pengo
A1 Chris Kosky
A1 Joerg Steier
YR 2014
UL http://erj.ersjournals.com/content/44/Suppl_58/P2236.abstract
AB Background Polysomnography (NPSG) is the gold standard to diagnose obstructive sleep apnoea (OSA) but nocturnal pulse oximetry could be an easy alternative. We investigated the correlation between the oxygen desaturation index (ODI>3%) and the NPSG derived apnoea-hypopnoea-index (AHI) to determine the accuracy of nocturnal pulse oximetry.Patients&Methods Consecutive patients attending our sleep disorders centre for NPSG were included. Data were analysed for age, sex, BMI, AHI and ODI>3%. The study population was classified according to BMI and the accuracy of ODI predicting AHI was calculated.Results 610 patients (54.9%m, age 41.9(14.7)y, BMI 28.3(6.6), AHI 5.3(9.2)/h, ODI>3% 6.5(10.5)/h) were included within the study. Of these 32.5% (55.1%m, age 44.9(13.7)y, AHI 8.2(11.3)/h, ODI>3% 11.1(13.7)/h) were obese and 67.5% (54.9%m, age 40.4(14.9)y, AHI 3.9(7.7)/h, ODI>3% 4.3(7.7)/h) were non-obese. The accuracy of ODI to predict NPSG-AHI was reduced with increasing BMI (non-obese: sensitivity 81%, CI:60.6%-93.4% and specificity 96.9%, 94.6%-98.4%, obese: sensitivity 79.4%, 62.1%-91.3%, specificity 88.4%, 82.5%-92.9%). The correlation between AHI and ODI>3% was high (R2 of 0.804; p<0.0001), with an area under the curve (AUC) of 0.950 for the whole group; for non-obese patients the AUC was 0.964 vs 0.914 (p=0.17) in obese patients.Conclusion ODI>3% as measured by nocturnal pulse oximetry, compared to AHI, is within the range of the 5% acceptable error margin. A wider use of nocturnal pulse oximetry as a cost-effective case finding tool for OSA in the general population can help to facilitate access to sleep services and accelerate time to treatment.