Fig. 1.

The association between different levels of risk for obstructive sleep apnoea–hypopnoea syndrome (OSAHS) according to the Berlin questionnaire and the level of multimorbidity. Patients whose responses qualified as high risk in at least two sections of the Berlin questionnaire were assigned a high risk for OSAHS, those who qualified in a single section of the questionnaire were assigned to a low risk for OSAHS, and those who did not qualify in any of the sections of the questionnaire were assigned to no risk for OSAHS. The vertical axis presents the prevalence of each level of multimorbidity within each level of OSAHS risk