From the Guidelines
The Oxygen Desaturation Index (ODI) is defined as ≥ 3% arterial oxygen desaturations/hour, which correlates with the Apnea-Hypopnea Index (AHI) in assessing sleep apnea severity, as indicated by the American Academy of Sleep Medicine 1.
Key Points to Consider
- ODI measures the number of times per hour that a patient's oxygen saturation levels drop by 3% or more, which can be an indicator of sleep apnea severity.
- AHI, on the other hand, captures all breathing disturbances, including those without significant desaturation, making it a more comprehensive measure of sleep apnea severity.
- The correlation between ODI and AHI is important, as it allows clinicians to use ODI as a screening tool when full polysomnography is not available, as seen in the treatment of obstructive sleep apnea syndrome (OSAS) with mandibular advancement devices 1.
Clinical Implications
- For accurate diagnosis and treatment planning, ODI should ideally be used alongside other clinical assessments, such as AHI measurement and clinical presentation.
- When significant discrepancies exist between ODI and clinical presentation, a full sleep study with AHI measurement remains the gold standard for diagnosis and treatment decisions.
- The treatment of OSAS with oral appliances (OA) has been shown to improve nocturnal oxygenation, including oxygen desaturation index and minimal oxygen saturation, highlighting the importance of considering ODI in treatment planning 1.
From the Research
Correlation Between ODI and AHI
- The correlation between Oxygen Desaturation Index (ODI) and Apnea-Hypopnea Index (AHI) has been studied in various research papers 2, 3, 4, 5, 6.
- A study published in Cureus found a significant correlation between ODI and AHI (r=0.734, p=0.001) 2.
- Another study published in Sleep Science found a significant correlation between ESS and AHI, ODI, with the highest correlation being with AHI, and a good concordance of 87.32% between AHI and ODI in classifying severity of OSA 3.
- A study published in Nature and Science of Sleep found a correlation between the AHI and ODI of 0.97 overall, 0.94 for supine, and 0.96 for non-supine recording times (all p<0.001) 4.
- A study published in American Journal of Translational Research found that ODI showed a high diagnostic value for OSA (area under curve (AUC) = 0.823,95% CI: 0.730-0.917) 5.
- A systematic review published in The Laryngoscope found that significant heterogeneity exists in studies comparing ODI and AHI, but consideration should be given for diagnosing adult OSA with a 4% ODI of ≥ 15 events/hour 6.
Diagnostic Value of ODI
- The diagnostic value of ODI for OSA has been evaluated in several studies 2, 3, 5, 6.
- A study published in Cureus found that the sensitivity, specificity, and diagnostic accuracy of home oximetry in detecting OSA (ODI>5) were 69%, 100%, and 71%, respectively 2.
- A study published in Sleep Science found that an ODI>20 has a sensitivity of 96.6% and specificity of 69.6% in diagnosing severe OSA 3.
- A study published in American Journal of Translational Research found that the combination of ODI, LSpO2, and TS 90% demonstrated a high diagnostic value for OSA (AUC = 0.939,95% CI: 0.890-0.989) 5.
- A systematic review published in The Laryngoscope found that consideration should be given for diagnosing adult OSA with a 4% ODI of ≥ 15 events/hour and for recommending further evaluation for diagnosing OSA with a 4% ODI ≥ 10 events/hour 6.