After what type of study is the MSLT not recommended to be conducted the following morning?

The Multiple Sleep Latency Test (MSLT) is designed to measure the time it takes for a person to fall asleep in a quiet environment during the day. However, it is not recommended to be conducted after a split-night sleep study. A split-night sleep study involves diagnosing and treating obstructive sleep apnea (OSA) in one night. The initial part of the night is focused on gathering baseline sleep data, while the second part is dedicated to administering Continuous Positive Airway Pressure (CPAP) therapy if significant OSA is identified.

Conducting an MSLT the following morning after a split-night study can lead to inaccurate results because the sleep deprivation caused by the first part of the night may unduly influence sleep onset latency (how quickly a person falls asleep). Patients may also still be experiencing effects of sleep fragmentation or residual influences from the newly introduced CPAP treatment. Therefore, to ensure valid and reliable measurements of daytime sleepiness and sleep latency that the MSLT aims to achieve, it is best conducted under more stable and controlled conditions, usually following a full overnight polysomnography (PSG) where the patient is not subjected to intervention that may affect their sleep architecture.

In contrast, a baseline overnight PSG, a full overnight PSG, or