The modified Baveno classification for obstructive sleep apnoea: design of a pan-European prospective study

Background Using the apnoea-hypopnoea index (AHI) as the sole determinant for treating obstructive sleep apnoea (OSA) is being critically discussed. The modified Baveno classification is a multicomponent grading tool combining respiratory disturbance, symptoms and cardiovascular disease (CVD) risk assessment to guide treatment of OSA. Retrospective analyses of an existing database showed that treatment according to this classification resulted in significantly improved symptoms and cardiovascular parameters. We report the design of the first prospective study to evaluate the modified Baveno classification. Methods Patients with OSA (≥40 years) recruited in this multicentre, prospective, observational long-term follow-up study will be treated with OSA-specific therapy according to the modified Baveno classification. Patients with AHI≥30/h or with established CVD, severe renal disease, diabetes with end-organ damage, difficult-to-treat hypertension or chronic/recurrent atrial fibrillation are associated with strong treatment indication. For the remaining patients, SCORE2/SCORE2-OP/SCORE2-diabetes risk assessment of CVD together with symptom scores, determines the strength of treatment indication. The first hierarchical primary outcome is change in office systolic blood pressure (SBP), followed by Epworth Sleepiness Scale. Follow-up will occur at 6-,12-, 24- and 36-months from baseline. Retrospective data analysis revealed a mean change in SBP of −5±14 mmHg in 393/1081 patients. A power of 99.9 % with a two-sided alpha of 0.001 results in a sample size of 894. The target sample size is 1800 patients, assuming a drop-out rate of 50 % at 3 years. Discussion This study investigates the clinical relevance of the modified Baveno classification for OSA severity assessment and treatment decision making in clinical practice.