Apnoea-Hypopnoea-Indices Determined Via Continuous Positive Airway Pressure vs Those Determined by Polysomnography

Inclusion Criteria: * All (full scientific) study designs and publication types written in English and reporting Bland-Altman test results (or other tests suggesting the presence of the required data) between simultaneous, paired, polysomnography (PSG)-derived AND Continuous Positive Airway Pressure (CPAP)-derived data describing sleep disordered breathing. Exclusion Criteria: * Duplicates * Does not refer to a full scientific article (e.g. case reports are excluded). * Meta-analysis * Paediatric populations (populations \<18 years are excluded). * Absence of appropriate paired results: synchronized polysomnography (PSG)-derived AND Continuous Positive Airway Pressure (CPAP)-derived data must be reported for ≥1 of the following measures: Apnoea-Hypopnoea-Indices (AHI), Apnoea-Indices (AI), Hypopnoea-Indices(HI), respiratory disturbance index (RDI), respiratory effort related arousals (RERA). * Absence of appropriate test comparing paired results: the study must use ≥1 of the fol-lowing tests to compare the previously mentioned PSG-vs-CPAP-derived data: a bland-altman or correlation test, other conformity tests, tests of differences in centrality. * Inappropriate PSG scoring 1: PSG-derived variables must be coded following the American Academy of Sleep Medicine 2007 (or more recent) guidelines. * Inappropriate PSG scoring 2: PSG-derived variables must be scored manually. * Inappropriate PSG scoring 3: oxygen desaturation level used for scoring must be mentioned and at 3% or 4%. * Inappropriate CPAP description: brand/device names must be mentioned.