The number of apneas and hypopneas per hour of sleep. Apneas are the cessation of airflow at the nostrils and mouth for at least 10 seconds as determined using nasal-oral thermistor or device flow. Hypopneas is shallow breathing in which the air flow in and out of the airway is significantly reduced as detected by nasal pressure or device flow - often associated with oxygen desaturation of 4% or EEG arousal.

A central sleep scorer was utilized to review of the overnight PSGs and count the number of apneas and hyopneas per hour. The index is the average number for apneas+hyopneas per hour.

The number of apneas and hypopneas per hour of sleep while in REM (rapid eye movement) and in NREM (non-rapid eye movement)

A central sleep scorer was utilized to review of the overnight PSGs and count the number of apneas and hyopneas per hour while in REM vs. NREM.

Data was not scorable for NREM.

The number of central apneas divided by the number of hours of sleep. Central apneas are the cessation of airflow at the nostrils and mouth for at least 10 seconds that is associated with the absence of inspiratory effort.

A central sleep scorer was utilized to review of the overnight PSGs and count the number of central apneas per hour.

Obstructive sleep apnea (OSA) is the most common type of sleep apnea and is caused by complete or partial obstructions of the upper airway.

A central sleep scorer was utilized to review of the overnight PSGs and count the number of obstructive apneas per hour.

Mixed sleep apnea is a combination of both obstructive and central sleep apnea symptoms

A central sleep scorer was utilized to review of the overnight PSGs and count the number of mixed apneas per hour.

Hypopneas are characterized by shallow breathing in which the air flow in and out of the airway is significantly reduced as detected by nasal pressure or device flow - often associated with oxygen desaturation of 4% or EEG arousal.

A central sleep scorer was utilized to review of the overnight PSGs and count the number of hyopneas per hour.

Sleep onset latency is the length of time that it takes to accomplish the transition from full wakefulness to sleep, normally to the lightest of the non-REM sleep stages. This found by reviewing the number of minutes in the PSG it took from lights off until the lightest non-REM sleep.

Rapid eye movement latency is the time from the sleep onset to the first epoch of REM sleep; therefore, it depends on the patient's sleep latency.

This data was not part of the scoring PSG criteria and therefore not collected.

Wake after sleep onset refers to periods of wakefulness occurring after defined sleep onset. This was calculated by adding the total number of minutes the participant was awake after sleep onset.

Total sleep time is the total time the participant was asleep after sleep onset. This is calculated by adding the total number of minutes the participant was asleep during the night after sleep onset.

Sleep efficiency is a measure of how much a participant slept over the night. This is calculated by comparing the total sleep time and the total recording time * 100.

These measures are the amount of time patients spent in each stage of sleep in minutes.

The number of arousals and awakenings is registered in the study, and reported as a total number and as a frequency per hour of sleep, which is referred to as an index. The higher the arousal index, the more tired you are likely to feel, though people vary in their tolerance of sleep disruptions.

Measure of oxygen saturation as measured by a pulse oximetry over the course of the night.

This is the measure of the Apnea Hypopnea Index as measured by using a modified hypopnea rule. The modified hypopnea rule is a scoring change when AHI changes due to central vs obstructive apneas.

During scoring of the PSG the modified hypopnea rule wasn't utlized therefore this data is not provided.

The AHI during epochs for which leak is determined to exist within acceptable limits occurs is the same calculation during AHI is normally calculated just in a 30 second (epoch) time period.

This was not part of the standard scoring of the PSG, therefore this was not calculated