Beyond the Apnoea–Hypopnoea Index: Towards Personalised Care of Patients with Suspected Obstructive Sleep Apnoea Through Clinical Phenotyping and Physiological Stratification

The apnoea–hypopnoea index (AHI) remains central to the diagnosis of obstructive sleep apnoea (OSA), but it incompletely captures both clinical heterogeneity and the physiological burden of respiratory events. We propose a phenotype-guided framework with a common initial clinical assessment followed by two complementary pathways according to the patient’s predominant clinical need: a symptom-oriented pathway based on pre-test clinical phenotyping, and a cardiovascular risk-oriented pathway in which directly measured hypoxic burden (HB), complemented by the respiratory event-related pulse-rate response, may eventually support physiological stratification. In our single-centre cohort of 5385 referrals, three predominantly symptomatic phenotypes accounted for 56.5% of patients and two paucisymptomatic phenotypes (A and E) for 43.5%; these groups had overlapping AHI distributions but different clinical profiles and needs. The reported AUC of 0.87–0.95 reflects supervised reproduction of internally derived cluster labels, not prediction of clinical outcomes or CPAP benefit. HB and pulse-rate response remain candidate physiological markers: evidence for treatment-effect modification derives from post hoc analyses and does not establish validated treatment-allocation criteria. Pre-test phenotyping is sufficiently developed to justify prospective, external, multicentre validation, whereas physiological integration requires methodological standardisation and prospective evaluation before individual treatment decisions can be guided by these markers.