Sleep scoring and results

From a recording to a report

A sleep study produces hours of continuous signals: brain waves, eye movements, breathing, blood oxygen, heart rate and muscle activity. Scoring is the step that turns those hours into counts and percentages, such as how many breathing pauses occurred and how long you were asleep. Interpretation comes after scoring, when your provider reads the numbers alongside your history. MedlinePlus says the provider reviews all the results and, if appropriate, creates a treatment plan.

The words below are the ones that come up most, so a conversation with the provider goes further.

The terms you will see

Polysomnogram

The full-night recording itself. It records brain waves, eye movements, breathing rate, heart rate and muscle electrical activity.

Apnea-hypopnea index (AHI)

A count of sleep apnea episodes. MedlinePlus notes that more than five episodes probably indicates sleep apnea. Your provider reads the number in context, so treat it as a term to ask about and not a verdict.

Sleep efficiency

Minutes asleep compared with total time in bed. A long time in bed without sleeping gives a low efficiency.

Oxygen desaturation index (ODI)

The number of times blood oxygen drops during sleep. MedlinePlus says a level below 90 percent is abnormal.

Heart rate

Measured throughout the night. MedlinePlus gives 60 to 100 beats per minute as the normal range.

Sleep stages

The brain wave pattern shows how the night divided into lighter sleep, deeper sleep and rapid eye movement (REM) sleep.

Oximeter

The small clip on a finger or ear that reads blood oxygen.

Lab and home reports differ in detail

A lab study records brain waves and so can describe sleep stages. A home test records breathing rate, heart rate, blood oxygen and snoring, so its report centers on breathing and oxygen. The home and lab guide compares what each records.

How the results reach you

Patients who stay overnight may complete a questionnaire about their sleep the next morning, and that answer sits alongside the numbers. The provider who ordered the study reviews everything. MedlinePlus says that questions about results go to the provider, so a report in hand is a reason to book that conversation rather than a reason to guess.

Questions to ask about your own report

• Which of these numbers matter most in my case?
• How does this study compare with what we expected before it?
• What happens next, and when?
• Is another study needed, such as a daytime test?
• Can I have a copy of the report?

If your sleep study was ordered for a dental reason, the guide to dental sleep medicine explains where dentists fit in.