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Apnea-hypopnea index: time to wake up

Authors Shahar E

Received 4 February 2014

Accepted for publication 28 February 2014

Published 5 April 2014 Volume 2014:6 Pages 51—56


Checked for plagiarism Yes

Review by Single-blind

Peer reviewer comments 2

Eyal Shahar

Division of Epidemiology and Biostatistics, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA

Abstract: Despite the widespread use of the apnea-hypopnea index in research, its scientific and statistical properties have not been examined thoroughly. The index may be viewed either as a rate (number of events per hour of sleep) or as a ratio of two variables (number of events/number of hours of sleep). When considered as a rate, the apnea-hypopnea index may be modeled as the dependent variable, provided that researchers explicitly state which physical property they assume to be measuring. On the other hand, the index is rarely, if ever, the preferred model of exposure to sleep-disordered breathing (an independent variable), regardless of whether it is considered a rate or a ratio variable. Continued indiscriminate use of the apnea-hypopnea index in sleep research should be discouraged.

Keywords: apnea-hypopnea index, respiratory disturbance index, ratio variables, rates

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