Avi Sadeh

Professor of Psychology Tel-Aviv University, Israel April 13, 1957–September 19, 2016
Published:December 13, 2016DOI:
      I am honored to pay tribute to Avi Sadeh, who passed away in September. He was one of the world's most distinguished pediatric sleep researchers. He was also a talented clinician and educator who helped many families and children efficiently resolve sleep and daytime problems.
      His contributions to pediatric sleep research span methodological and scientific discoveries that have pushed the field forward. His work has informed recommendations made by key policy makers such as the American Academy of Pediatrics (school start time recommendations), and the National Sleep Foundation regarding optimal sleep durations for children and adolescents.
      Professor Amy R. Wolfson, a leader in child and adolescent sleep research and Associate Editor of Sleep Health, said of Dr. Sadeh: “He was the one who integrated the use of actigraphy into pediatric sleep research. Without his work, we would not be using this key measure, which allows us to estimate sleep patterns in a reliable way in the child's natural environment and to estimate duration and timing of sleep in fairly large-scale studies. This methodology paved the way for work that has provided the foundation for significant findings and impacted the conversation on important policies, such as through the American Academy of Pediatrics' recommendation for delaying school start times in the US.”
      Indeed, Dr. Sadeh contributed to dramatically increasing the use of activity-based sleep–wake monitoring, or actigraphy, for assessing sleep in clinical research and as a diagnostic tool in sleep medicine. This is particularly important for the study of sleep in children, where the collection of objective data often required children to sleep in laboratory settings. This was difficult for parents, expensive, of limited duration, and potentially prone to affecting the sleep, emotions, behavior, and cognition of the children—which were the very functions the researchers were trying to study. Dr. Sadeh's work on validating actigraphy as a reliable measure for ambulatory home-based objective assessment of sleep patterns helped overcome the inevitable “trade-off” between the quantity and quality of objective sleep data collected and the extent of interference with natural sleep. During the course of his career, and in a large part thanks to his work, actigraphy has become a major assessment tool in pediatric sleep research.
      Another key methodological contribution of Dr. Sadeh's work was his use of home-based experimental paradigms to investigate potential causal relationships between sleep and daytime functioning. By using actigraphy in the child's natural environment, asking participants to manipulate sleep for several successive nights at home, and measuring the impact of these changes on daytime parameters, Dr. Sadeh made key discoveries regarding the impact of experimentally extending or restricting sleep on a range of outcome measures that are relevant to children's health, daytime behavior, adjustment, and academic performance.
      Dr. Merrill Wise, a leader in clinical sleep medicine, said of Dr. Sadeh: “His work empirically demonstrating the close interplay between sleep, emotion, and behavior provided important validation for the clinical observations I make every day in my encounters with children with sleep disorders. These empirical data provided important tools for clinicians like me, as we use the information to explain to parents, children, and adolescents how treating a sleep disorder could not only help the patient sleep better, but also help them be more successful and better regulate their mood, emotions, and behavior.” Indeed, Dr. Sadeh's work has contributed to demonstrating such links in both typically-developing children and those with emotional and behavioral challenges.
      As our field is seeking to establish recommended amounts of sleep for children and adolescents for healthy development, Dr. Sadeh's work stands out for its strength, and his findings offer an important source of data as we attempt to empirically determine the association between sleep and development at different ages.
      Earlier than expected, Dr. Avi Sadeh's work has been stopped. However, he has inspired the work of countless students and colleagues. His legacy will continue to inspire generations of sleep researchers, clinicians, and students, and will contribute to helping children with sleep disorders and their families.