What does an Apnea-Hypopnea Index (AHI) of 6.9 indicate?

What Does an AHI of 6.9 Indicate?

An AHI of 6.9 indicates mild obstructive sleep apnea (OSA), as it falls within the 6-20 events per hour range defined by the American Society of Anesthesiologists. 1

OSA Severity Classification

Your AHI of 6.9 places you in the mild OSA category according to established severity thresholds 1:

• None/Normal: AHI 0-5 events/hour 2
• Mild OSA: AHI 6-20 events/hour 1
• Moderate OSA: AHI 21-40 events/hour 1
• Severe OSA: AHI >40 events/hour 1

This means you are experiencing an average of approximately 7 breathing pauses or significant reductions in airflow per hour during sleep 1.

Clinical Significance

What This Number Represents

• The AHI measures the combined number of complete breathing pauses (apneas) and partial reductions in airflow (hypopneas) per hour of sleep 2
• An AHI ≥5 is the threshold where OSA diagnosis begins, and your value of 6.9 exceeds this cutoff 3
• The American Academy of Sleep Medicine considers AHI <5 as normal, so your result indicates abnormal sleep-disordered breathing 2

Important Context About Your Result

Your AHI should be interpreted alongside your symptoms and clinical presentation, not in isolation. While the number indicates mild OSA, the clinical impact varies significantly between individuals 1, 4.

Critical Caveats in Interpretation

Scoring Method Variations

The specific AHI value you received depends heavily on which hypopnea scoring criteria your sleep center used 3, 2:

• Using the AASM-recommended criteria (30% flow reduction with ≥4% oxygen desaturation), AHI values are approximately 70% lower than with older Chicago criteria 3, 2
• An AHI of 6.9 using recommended criteria might correspond to an AHI of approximately 12-14 using alternative scoring methods 2
• This scoring variability is particularly important in borderline cases like yours, where you're just above the diagnostic threshold 2

Night-to-Night Variability

Mild OSA shows the highest night-to-night variability in AHI measurements 5:

• Approximately 27% of AHI variability is due to intra-individual factors (meaning your AHI could vary significantly on different nights) 5
• Patients with mild OSA (AHI 5-15) demonstrate higher variability compared to those with more severe disease 5
• If clinical suspicion remains high despite your borderline result, a repeat sleep study may be warranted 3

Limitations of AHI Alone

The AHI does not capture several clinically important factors 6, 4, 7:

• Duration of individual breathing events (longer events cause more severe oxygen desaturation) 6, 7
• Depth of oxygen desaturations 6, 7
• Sleep architecture disruption 1
• Respiratory events occurring during brief awakenings (which aren't counted but still cause symptoms) 3, 1

Patients with similar AHI values can have dramatically different cardiovascular stress and symptom burden 6, 7, 8.

Next Steps

When Polysomnography is Recommended

The American Academy of Sleep Medicine recommends full polysomnography (rather than home testing) if you have 3:

• Significant cardiorespiratory disease
• Potential respiratory muscle weakness
• Chronic opioid use
• History of stroke
• Severe insomnia

If Home Sleep Testing Was Negative or Inconclusive

If your AHI of 6.9 came from home sleep apnea testing and clinical suspicion remains high, polysomnography should be performed for definitive diagnosis 3.

Clinical Correlation Required

The decision to treat should be based on your symptoms (daytime sleepiness, fatigue, witnessed apneas, cardiovascular risk factors) combined with the AHI, not the AHI number alone 3, 4. The American Academy of Sleep Medicine emphasizes that OSA prevalence estimates using AHI ≥5 combined with clinical symptoms differ significantly from using AHI alone 3.