The AASM scoring manual: a critical appraisal

Purpose of review Summarize recently published studies and critiques evaluating the effects of the American Academy of Sleep Medicine (AASM) Sleep Scoring Manual. Recent findings Only a few retrospective studies have been published evaluating the new AASM Scoring Manual. These have shown that when scoring polysomnograms (PSGs) using the AASM rules compared to previous standards and guidelines: increased amount and percentage of sleep time in Non-Rapid Eye Movement Sleep (NREM) 1 (N1) and N3 sleep, and decreased NREM 2 (N2) sleep; improved interscorer reliability when scoring sleep stages in adults; large differences in apnea-hypopnea indexes (AHIs) using different hypopnea scoring definitions; and PSGs scored using the 'recommended' hypopnea definition in the new manual identified no significant sleep disordered breathing in 40% of lean individuals with symptomatic OSA (AHI >= 5/h by 1999 'Chicago' criteria) and a favorable response to treatment. Summary Two years have passed since the AASM Scoring Manual was published, garnering less criticism than was feared by those who developed it. The improvement in interscorer reliability using the Manual is heartening since this goal shaped many of the choices made. The alternative hypopnea rule should be endorsed as a recommended option. The AASM Scoring Manual provides a foundation upon which we all can build rules and methods that quantify the complexity of sleep and its disorders. Multicenter validation and refinement of the Manual is encouraged.