Understanding your sleep apnoea diagnosis results

Your diagnostic sleep study report

Your doctor ordered an overnight sleep study (also called a polysomnogram or PSG), either in a sleep centre or your home, to determine if you have sleep apnoea. After you complete the sleep study, your doctor will give you the results and discuss what to do next.

You may be given a copy of your sleep study report. If so, the report may be filled with terms you haven't seen before. Below is an example of what is typically included in a diagnostic sleep study report along with descriptions of what is being reported.

Diagnostic sleep study report

Name: Doe, John

Height: 73"

Test Date: 8/9/2012

DOB: 21/1/1973

Weight: 91 kg

Age: 39 YRS

BMI: 27

Referring physician: Dr. Acula

Sex: Male

Test: #136

Mr. Doe is a 39 year-old male referred by Dr. Smith with symptoms of snoring and excessive daytime sleepiness. His bed partner reports that Mr. Doe has apnoea episodes and wakes up gasping for breath several times during the night. The patient is 73 inches tall and 91 kg with a BMI of 27.0. He is significant for a Mallampati class 3 oropharnyx.

The medical history is significant for hypertension. His current medications are Lisinopril and Prilosec. The patient's normal bedtime is 10:30 pm. A full in-lab Diagnostic Polysomnography was ordered to rule out the diagnosis of obstructive sleep apnoea (OSA).

Apnoea/hypopnea index	18.8
Total respiratory events	104
Central apnoeas Central hypopneas	12
Mixed apnoeas	1
Obstructive apnoeas	91
Obstructive hypopnoeas	0
RERA count / RERA index	0 / 0.0/hr
RDI	0.0

Respiratory events by body position
Supine AHI	31.5
Lateral AHI	35.4
Prone AHI	0.0

Oxygen saturations
Mean SpO2	96%
Lowest SpO2 during sleep	84%

Limb movements
Leg movements	562 / 81.2
PLMS	453 / 65.4
PLMS Arousals	55 / 7.9

Sleep times
Lights out	10:07:44 PM
Lights on	5:25:02 AM
Total bed time (min)	437.3
Total sleep time (min)	357.0


Sleep efficiency	81.6%
Sleep latency (min)	11.6
REM latency (min)	33.1
WASO (min)	27.2

	REM	NREM	Arousals	Awakenings	Ar + Aw	Ar + Aw Index
Respiratory events recorded in each category:	0	16	21	6	27	3.9
Snore:	11	25	58	15	73	10.5
Spontaneous:	10	12	28	3	31	4.5
Total:	21	53	107	24	131	18.9
Arousal Index:	18.0	12.2	15.5	3.5	18.9	- -

The report above is an example of a diagnostic sleep report, where you are tested to determine if you have a sleep disorder.

Other reports include:

a CPAP titration study report, which is the result of a separate study to fit you with a CPAP device and mask after you have been diagnosed with sleep apnoea
a split-night sleep study report, in which a CPAP titration study on the same night as an in-lab sleep study. This is known as a split-night sleep study. The CPAP titration occurs in the second half of the night.

Apnoea/hypopnea index (AHI)

Apnoea/hypopnea index (AHI)
Apnoea/hypopnea index (AHI)
Total respiratory events
Total respiratory events

Total of central apnoeas and hypopnoeas, obstructive apnoeas and hypopnoeas, and respiratory effort-related arousals or RERAs.
Central apnoeas
Central apnoeas
Central hypopneas
Central hypopneas

50% reduction in both airflow and respiratory effort.
Mixed apnoeas
Mixed apnoeas
Obstructive apnoeas
Obstructive apnoeas
Obstructive hypopneas
Obstructive hypopneas

50% decrease in airflow but respiratory effort remains intact.
RERA count / RERA index
RERA count / RERA index

A sequence of breaths characterised by marked decreased in airflow for at least 10 secs, with increased respiratory effort, no desaturation and which leads to an arousal from sleep.
RDI
RDI

All apnoeas + hypopnoeas + RERAs / Total sleep time (hrs).

Arousal Index

REM
REM

Rapid eye movement sleep.
NREM
NREM

Non rapid eye movement sleep.
Arousals
Arousals

Interruptions of sleep lasting 3 to 15 seconds.
Awakenings
Awakenings

Arousal less than 15 seconds.
Ar + Aw
Ar + Aw

Total arousals and awakenings.
Ar + Aw Index
Ar + Aw Index

Total arousals and awakenings per hour.

Respiratory events by body position

Oxygen saturations

Limb movements

Sleep times

Sleep efficiency
Sleep efficiency

The number of minutes of sleep divided by the number of minutes in bed.
Sleep latency (min)
Sleep latency (min)

How long to fall asleep.
REM latency (min)
REM latency (min)

How long to enter rapid eye movement sleep phase.
WASO (min)
WASO (min)

Wake after sleep onset, or the amount of time spent awake after sleep has been initiated and before final awakening.

Understanding your sleep study results

Your diagnostic sleep study report

Diagnostic sleep study report