What are the types of home sleep study devices and which is first‑line for an adult with suspected obstructive sleep apnea and no significant pulmonary or neurologic disease?

Types of Home Sleep Study Devices and First-Line Recommendation

For an adult with suspected obstructive sleep apnea and no significant pulmonary or neurologic disease, Type 3 home sleep apnea testing (HSAT) devices are first-line, measuring at minimum airflow, respiratory effort, and oxygen saturation. 1

Classification of Home Sleep Study Devices

Home sleep study devices are traditionally classified into four types, though this system has limitations with newer technologies:

Type I: In-Laboratory Polysomnography

• Full attended polysomnography with comprehensive monitoring including EEG, EOG, EMG, airflow, respiratory effort, oxygen saturation, ECG, and body position 1
• Considered the gold standard but not a "home" device 1

Type II: Comprehensive Portable Polysomnography

• Uses the same monitoring sensors as Type I PSG but unattended, allowing home use 1
• Not recommended for clinical use in either attended or unattended settings due to inadequate available data, absence of sensitivity/specificity data, and low level of evidence 1

Type III: Modified Portable Sleep Apnea Testing (First-Line for Appropriate Patients)

• Measures limited cardiopulmonary parameters: minimum of two respiratory variables (airflow and/or respiratory effort), oxygen saturation, and a cardiac variable (heart rate or ECG) 1
• This is the recommended first-line device type for uncomplicated patients with high pretest probability of moderate-to-severe OSA 1
• Specific sensor configurations include:
  • Nasal pressure for airflow detection 1
  • Thoracic and abdominal respiratory inductance plethysmography (RIP) belts for effort 1
  • Pulse oximetry for oxygen saturation 1
  • Heart rate or ECG monitoring 1
  • Body position sensor 1

Type IV: Single or Dual Parameter Devices

• Measure only 1-2 parameters, typically oxygen saturation and heart rate, or just airflow 1
• Not recommended for diagnosing OSA due to insufficient data 1

Alternative Technologies Outside Traditional Classification

Peripheral Arterial Tonometry (PAT) Devices:

• Use arterial tone, actigraphy, and oximetry 1
• Demonstrated adequate diagnostic accuracy with receiver operating characteristic areas under the curve of 0.82-0.87 1
• Considered acceptable for OSA diagnosis when used appropriately 1, 2

Critical Requirements for Type 3 HSAT Use

Patient Selection Criteria (All Must Be Met):

• High pretest probability of moderate-to-severe OSA 1
• No significant comorbid cardiopulmonary disease (COPD, congestive heart failure excluded) 1, 3
• No comorbid sleep disorders (narcolepsy, central sleep apnea, restless leg syndrome excluded) 1, 3
• Not safety-sensitive transportation workers (airplane pilots, commercial drivers require in-laboratory PSG) 3

Technical Requirements:

• Minimum 4 hours of good quality data from adequate flow and oximetry signals during the habitual sleep period 1
• Testing must be administered by an accredited sleep center under supervision of a board-certified sleep medicine physician 1
• Manual or combined automatic/manual scoring with careful review of raw data 1

Management Pathway Requirements:

• Must include a PAP therapy initiation protocol 1
• Early follow-up within 2-7 days after HSAT by skilled technical staff 1
• PSG titration studies available for patients failing APAP therapy 1

Important Limitations and Pitfalls

Type 3 Devices Do Not Measure Sleep:

• Use recording time rather than total sleep time in the denominator, typically underestimating the AHI compared to PSG 1
• Cannot detect sleep architecture, arousals, or periodic limb movements 1

Critical Follow-Up Requirements:

• Symptomatic patients with negative or nondiagnostic Type 3 studies must undergo in-laboratory PSG to determine the cause of symptoms 1
• Patients with positive Type 3 studies may need subsequent PSG for CPAP titration if APAP is not used 1

Technical Failure Rates:

• Unattended studies have higher technical failure rates (reported 4-24% in various studies) due to lack of real-time monitoring 1
• Sensor displacement, battery failure, and inadequate recording duration are common issues 1

When In-Laboratory PSG Is Mandatory

Absolute Indications:

• Comorbid respiratory disease (COPD, hypoventilation syndromes) 3
• Comorbid neurologic disease 1
• Suspected central sleep apnea or other sleep disorders 1
• Safety-sensitive occupations (pilots, commercial drivers) 3
• Failed or nondiagnostic HSAT in symptomatic patients 1