Positional OSA part 1: Towards a clinical classification system for position-dependent obstructive sleep apnoea

Area of Science:

• Sleep Medicine
• Respiratory Medicine
• Clinical Diagnostics

Background:

• Physicians have long differentiated between positional obstructive sleep apnoea (POSA) and non-positional OSA.
• Recent advancements in positional therapy (PT) offer effective treatment for POSA, but lack standardized criteria for patient selection.
• Existing criteria, like Cartwright's 1984 arbitrary cut-off, hinder efficacy evaluation and comparison of PT outcomes.

Purpose of the Study:

• To introduce a novel classification system, the Amsterdam Positional OSA Classification (APOC).
• To identify patients most likely to experience significant improvement in OSA with PT.
• To facilitate multi-center data collection and comparison of PT results through a shared classification system.

Main Methods:

• A panel of three experts independently diagnosed POSA in 100 selected patients.
• Consensus was reached through group discussion to establish a gold standard for calibration.
• The Amsterdam Positional OSA Classification (APOC) was developed using the nominal group technique.

Main Results:

• The APOC criteria consider the percentage of total sleep time in the worst and best sleeping positions (WSP/BSP) and the apnoea-hypopnoea index (AHI) in the BSP.
• APOC categorizes patients into true positional, non-positional, and multifactorial groups based on OSA severity influenced by sleep position.
• APOC demonstrates superior sensitivity, specificity, PPV, and NPV compared to prior POSA criteria in identifying suitable candidates for PT.

Conclusions:

• The developed Amsterdam Positional OSA Classification (APOC) provides a standardized method for identifying patients who will benefit from positional therapy.
• APOC enhances the accuracy of patient selection for PT, improving treatment efficacy for obstructive sleep apnoea.
• This classification system is expected to improve data consistency and comparability across studies investigating positional therapy for OSA.