Introduction Actigraphy Has Been Used to Study Sleep for at Least the past 30 Years, since Kupfer Et Al1 Reported Significant and Substantial Correlations between Wrist Activity and Electroencephalogram (eeg)- Measured Movement and Wakefulness

ACTIGRAPHY HAS BEEN USED TO STUDY SLEEP FOR AT LEAST THE PAST 30 YEARS, SINCE KUPFER ET AL1 REPORTED SIGNIFICANT AND SUBSTANTIAL CORRELATIONS BETWEEN WRIST ACTIVITY AND ELECTROENCEPHALOGRAM (EEG)MEASURED MOVEMENT AND WAKEFULNESS IN 1972. Sufficient supportive data existed by 1995 to enable the Standards of Practice Committee of the American Sleep Disorders Association2 to support the use of actigraphy in evaluating certain aspects of sleep disorders. Representing an opposing view, Pollak et al concluded that their data “... disqualify actigraphy as an accurate sleep-wake indicator”3p957 and that “... it does not seem appropriate in 2001 to refer to inactivity defined by wrist actigraphy as “sleep” or to wrist activity as “wakefulness.”3p965 Were the conclusions of the Standards of Practice Committee of the American Sleep Disorders Association2 premature, incorrect, or both premature and incorrect? Are the conclusions drawn by Pollak et al3 fully supported by their data or do they go beyond their data? This article identifies and critically evaluates several theoretic and methodologic issues that are central to the controversy surrounding the use of actigraphy to assess sleep versus wakefulness.