Importance of Getting Enough Sleep and Daily Activity Data to Assess Variability: Longitudinal Observational Study

María Óskarsdóttir   ^{1, 2 *} , PhD ;   Anna Sigridur Islind   ^{1, 2 *} , PhD ;   Elias August   ^{1, 3} , PhD ;   Erna Sif Arnardóttir   ^{1, 2, 3, 4} , PhD ;   François Patou   ^{5, 6} , PhD ;   Anja M Maier   ^{5, 7} , PhD

¹ Reykjavik University Sleep Institute, School of Technology, Reykjavík University, Reykjavík, Iceland

² Department of Computer Science, Reykjavík University, Reykjavík, Iceland

³ Department of Engineering, Reykjavík University, Reykjavík, Iceland

⁴ Internal Medicine Services, Landspitali University Hospital, Reykjavík, Iceland

⁵ Department of Technology, Management and Economics, DTU-Technical University of Denmark, Copenhagen, Denmark

⁶ Oticon Medical, Copenhagen, Denmark

⁷ Department of Design, Manufacturing and Engineering Management, Faculty of Engineering, University of Strathclyde, Glasgow, United Kingdom

*these authors contributed equally