Title

Handling missing data in rest-activity time series measured by actimetry

Authors

André Comiran Tonon, Sono, Hospital de Clínicas de Porto Alegre (HCPA), Federal University of Rio Grande do Sul (UFRGS)Laboratório de Cronobiologia e , Porto Alegre, Brazil.
Luísa K. Pilz, Sono, Hospital de Clínicas de Porto Alegre (HCPA), Federal University of Rio Grande do Sul (UFRGS)Laboratório de Cronobiologia e , Porto Alegre, Brazil.
Guilherme Rodriguez Amando, Sono, Hospital de Clínicas de Porto Alegre (HCPA), Federal University of Rio Grande do Sul (UFRGS)Laboratório de Cronobiologia e , Porto Alegre, Brazil.
Débora Barroggi Constantino, Sono, Hospital de Clínicas de Porto Alegre (HCPA), Federal University of Rio Grande do Sul (UFRGS)Laboratório de Cronobiologia e , Porto Alegre, Brazil.
Rogério Boff Borges, Unidade de Bioestatística, Diretoria de Pesquisa, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.
Arthur Caye, Department of Psychiatry, School of Medicine, Universidade Federal do Rio Grande do Sul; Child and Adolescent Psychiatry Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
Fernanda Rohrsetzer, Psychiatry and Behavioral Sciences, Federal University of Rio Grande do Sul (UFRGS)Graduate Program , Porto Alegre, Brazil.
Laila Souza, Department of Psychiatry, School of Medicine, Universidade Federal do Rio Grande do Sul; Child and Adolescent Psychiatry Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
Helen L. Fisher, Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, ESRC Centre for Society and Mental Health, King's College London, London, UK.
Brandon A. Kohrt, Division of Global Mental Health, Department of Psychiatry, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia, US.
Valeria Mondelli, King's College London, Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience; National Institute for Health Research Mental Health Biomedical Research Centre, South London and Maudsley NHS Foundation Trust, London, UK.
Christian Kieling, Psychiatry and Behavioral Sciences, Federal University of Rio Grande do Sul (UFRGS)Graduate Program , Porto Alegre, Brazil.
Marco Idiart, Neurocomputational and Language Processing Laboratory, Institute of Physics, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
Antoni Diez-Noguera, Fisiologia, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de BarcelonaDepartment de Bioquimica i , Barcelona, Spain.
Maria Paz Hidalgo, Sono, Hospital de Clínicas de Porto Alegre (HCPA), Federal University of Rio Grande do Sul (UFRGS)Laboratório de Cronobiologia e , Porto Alegre, Brazil.

Document Type

Journal Article

Publication Date

3-30-2022

Journal

Chronobiology international

DOI

10.1080/07420528.2022.2051714

Keywords

Actigraphy; activity; biological rhythms; chronobiology; circadian rhythms; motor activity; sleep; sleep medicine

Abstract

A handling procedure of off-wrist episodes in actimetry time series of motor activity is presented using two records (regular . irregular sleep-wake cycle and daytime activity) of 14 consecutive days sampled in 1-minute epochs. We generated single missing value (NA) intervals of 1 h, 2 h, 4 h, 6 h, 12 h, and 24 h as well as random NA episodes following probabilistic rules to simulate real-life off-wrist episodes. Then, we replaced these episodes with "zeroes" (i.e., the default of immobility records), mean or median of the remaining 13 days corresponding to the missing bins. Single missing episodes of up to 12 h resulted in less than 5% variation from the original values. The irregular series showed higher variability in acrophase, MESOR, L5, M10 and RA compared to the regular series. Random missing allocation simulating real-life off-wrist episodes resulted in significant changes in most parameters, and the imputation of zeroes significantly increased the variance; however, replacing NA with mean or median resulted in patterns similar to those of NA. We recommend replacing 'zeroes' with NA whenever possible, given the risk of inflating invariance using zeroes. If the parameters cannot be computed in the presence of NA, we recommend using the weekly mean of corresponding timepoints.

Department

Psychiatry and Behavioral Sciences

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