Scoring variability between polysomnography technologists in different sleep laboratories

Examine the variability of polysomnography technologists from different sleep laboratories regarding scoring of polysomnograms.

Polysomnography is the gold standard to diagnose obstructive sleep apnea-hypopnea syndrome. There are criteria to score sleep stages and respiratory events. We sought to determine how different technologists would score the same tests using their laboratory's criteria.

Eleven technologists in nine different sleep laboratories which used the Oxford Medilog SAC system scored eleven sleep studies performed in the Medical University of South Carolina Sleep Disorders Laboratory utilizing their respective laboratory's scoring rules. All sleep studies were performed for evaluation of obstructive sleep apnea-hypopnea syndrome (OSAHS). The scored studies were returned and analyzed for variability.

Significant variability was present in scoring of both sleep and respiratory events with more variability demonstrated in respiratory event scoring. In four of the studies, diagnoses based on apnea-hypopnea indices (AHI) varied from none to moderate OSAHS depending on which technologist scored the study and in one study the diagnosis varied from none to severe OSAHS.

Clinicians should be aware that there is tremendous variability among polysomnography technologists regarding the scoring of polysomnograms. These differences are likely due to different rules used to score events as well as differences in the technologist's interpretation of the rules.