Apnea Hypopnea Index (AHI) Calculator

Formula

The formula to calculate the Apnea Hypopnea Index (AHI) is:

\[ \text{AHI} = \frac{\text{A} + \text{H}}{\text{T}} \]

Where:

\( \text{AHI} \) is the Apnea Hypopnea Index (events per hour)
\( \text{A} \) is the Total Number of Apnea Events
\( \text{H} \) is the Total Number of Hypopnea Events
\( \text{T} \) is the Total Sleep Time (hours)

What is an Apnea Hypopnea Index?

The Apnea Hypopnea Index (AHI) is a standard tool used to measure the severity of sleep apnea. It calculates the average number of times per hour of sleep that a person’s breathing stops (apnea) or becomes dangerously shallow (hypopnea). A higher AHI indicates more severe sleep apnea, with a score of 5-15 indicating mild sleep apnea, 15-30 indicating moderate sleep apnea, and a score over 30 indicating severe sleep apnea.

Example Calculation

Let's consider an example:

Total Number of Apnea Events (A): 30
Total Number of Hypopnea Events (H): 20
Total Sleep Time (T): 8 hours

Using the formula to calculate the Apnea Hypopnea Index:

\[ \text{AHI} = \frac{30 + 20}{8} = \frac{50}{8} = 6.25 \, \text{events per hour} \]

This demonstrates that with 30 apnea events, 20 hypopnea events, and a total sleep time of 8 hours, the AHI would be 6.25 events per hour, indicating mild sleep apnea.