1. What is the Apnea Hypopnea Index (AHI)?

The Apnea Hypopnea Index (AHI) is a measure of sleep apnea severity that represents the average number of apnea and hypopnea events per hour of sleep. It is the primary metric used to diagnose and classify the severity of obstructive sleep apnea.

2. How Does the Calculator Work?

The calculator uses the AHI equation:

Where:

• \( Apneas \) — Number of apnea events during sleep study
• \( Hypopneas \) — Number of hypopnea events during sleep study
• \( Sleep\ Hours \) — Total hours of sleep recorded

Explanation: The equation calculates the average number of breathing disturbances per hour of sleep, which helps classify sleep apnea severity.

3. Importance of AHI Calculation

Details: AHI is crucial for diagnosing sleep apnea severity, determining appropriate treatment options, and monitoring treatment effectiveness over time.

4. Using the Calculator

Tips: Enter the number of apnea events, hypopnea events, and total sleep hours from your sleep study. All values must be valid (non-negative numbers, sleep hours > 0).

5. Frequently Asked Questions (FAQ)

Q1: What do different AHI values indicate?
A: Normal: <5 events/hour; Mild: 5-15 events/hour; Moderate: 15-30 events/hour; Severe: >30 events/hour.

Q2: What's the difference between apnea and hypopnea?
A: Apnea is complete cessation of breathing for ≥10 seconds. Hypopnea is partial reduction in breathing (≥30% reduction) with oxygen desaturation or arousal.

Q3: How is AHI used in treatment decisions?
A: AHI severity guides treatment choices - from lifestyle changes for mild cases to CPAP therapy for moderate-severe cases.

Q4: Can AHI vary night to night?
A: Yes, AHI can fluctuate based on sleep position, alcohol consumption, medication use, and other factors.

Q5: Is home sleep testing accurate for AHI calculation?
A: Home tests provide good estimates but may undercount events compared to in-lab polysomnography, which is the gold standard.