Statistics for sleep and biological rhythms research: Longitudinal analysis of biological rhythms data

Elizabeth B. Klerman, Wei Wang, Andrew J.K. Phillips, Matt T. Bianchi

Research output: Contribution to journalReview ArticleResearchpeer-review

7 Citations (Scopus)


This article is part of a Journal of Biological Rhythms series exploring analysis and statistical topics relevant to researchers in biological rhythms and sleep research. The goal is to provide an overview of the most common issues that arise in the analysis and interpretation of data in these fields. In this article, we address issues related to the collection of multiple data points from the same organism or system at different times, since such longitudinal data collection is fundamental to the assessment of biological rhythms. Rhythmic longitudinal data require additional specific statistical considerations, ranging from curve fitting to threshold definitions to accounting for correlation structure. We discuss statistical analyses of longitudinal data including issues of correlational structure and stationarity, markers of biological rhythms, demasking of biological rhythms, and determining phase, waveform, and amplitude of biological rhythms.

Original languageEnglish
Pages (from-to)18-25
Number of pages8
JournalJournal of Biological Rhythms
Issue number1
Publication statusPublished - 1 Feb 2017
Externally publishedYes


  • Biological rhythms
  • Circadian rhythms
  • Longitudinal analyses
  • Periodicity
  • Statistics

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