What is another mandatory component required in an order for a polysomnography (PSG)?

The correct answer highlights the necessity for identifying the type of study being requested, such as a split-night polysomnography or a standard polysomnography. This specification is essential because it guides the clinical team in preparing appropriately for the evaluation and helps ensure that the study is conducted with the correct protocols based on the patient's needs.

Understanding the type of study required allows for proper scheduling, setup of equipment, and allocation of resources. Each type of polysomnography has its own specific procedures and protocols. For example, a split-night study involves conducting an initial part of the night to diagnose sleep apnea and then proceeding to treat it with continuous positive airway pressure (CPAP) if indicated, which requires different considerations than a full night study focused solely on diagnosis.

The other options, while valuable, do not represent mandatory components in the same way. Patient demographic information is important for administrative purposes but does not directly influence the execution of the study. Previous sleep study results can aid in understanding the patient's history but are not needed to initiate a new order. Insurance information is crucial for billing and reimbursement but is not a clinical requirement for conducting the sleep study itself.