WRISTOX2 is a reliable tool to diagnose obstructive sleep apnoea syndrome

Introduction Overnight pulse oximetry is an alternative to polysomnography (PSG) in diagnosing obstructive sleep apnoea syndrome, but its sensitivity is reported to be low. Aims To determine the (a) diagnostic accuracy, interobserver reliability and reliable oxygen desaturation index of 4% (ODI4) score at diagnosing obstructive sleep apnoea syndrome in children and (b) correlation between the apnoea hypopnoea index (AHI) with ODI4 and oxygen nadir between both PSG and oximetry. Methods This cross-sectional study included children aged 1–18 years old, undergoing a fully attended overnight PSG for suspected obstructive sleep apnoea syndrome. The Nonin 3150 WristOx2 ™ [Fig. 2] was worn simultaneously during the PSG. Poor oximetry recordings were excluded. Pulse oximetry was scored using the McGill Oximetry Score (MOS) whereby a score of 2–4 was positive for OSAS. Specificity, sensitivity, positive predictive values (PPV), negative predictive values (NPV) and interobserver reliability of the WristOx2 were calculated. Results One hundred and sixty-two children with a mean (SD) age of 9.3 (±3.5) years (range 2 years 6 months old - 17 years old) were included after excluding 18 children (poor oximetry data [n = 16] and incomplete PSG [n = 2]). Interobserver agreement of the WristOx2 was 0.8763 (95% CI:0.80, 0.95). WristOx2 had a sensitivity 50%, specificity 96.7%, PPV 96% and NPV 53% at diagnosing OSAS. ODI4 ≥ 2 events/hour in oximetry had a sensitivity of 97.6% and negative predictive value of 85.7% at diagnosing OSA. Conclusion Overnight pulse oximetry with the Nonin 3150 WristOx2 ™ is an accurate and reliable tool in diagnosing significant OSAS in children.