Recommendations for determining the validity of consumer wearable heart rate devices: expert statement and checklist of the INTERLIVE Network

JMM is partly funded by Private Stiftung Ewald Marquardt fur Wissenschaft und Technik, Kunst und Kultur. UE and JS are partly funded by the Research Council of Norway (249932/F20). ELS is supported by TrygFonden (grant number 310081). PBJ is supported by the Portuguese Foundation for Science and Technology (SFRH/BPD/115977/2016). PMG and FBO are supported by grants from the MINECO/FEDER (DEP2016-79512-R) and from the University of Granada, Plan Propio de Investigacion 2016, Excellence actions: Units of Excellence; Scientific Excellence Unit on Exercise and Health (UCEES); Junta de Andalucia, Consejeria de Conocimiento, Investigacion y Universidades and European Regional Development Funds (ref. SOMM17/6107/UGR). WJ is partly funded by Science Foundation Ireland (12/RC/2289_P2). AG is supported a European Research Council Grant (grant number 716657). This research was partly funded by Huawei Technologies, Finland.Assessing vital signs such as heart rate (HR) by wearable devices in a lifestyle-related environment provides widespread opportunities for public health related research and applications. Commonly, consumer wearable devices assessing HR are based on photoplethysmography (PPG), where HR is determined by absorption and reflection of emitted light by the blood. However, methodological differences and shortcomings in the validation process hamper the comparability of the validity of various wearable devices assessing HR. Towards Intelligent Health and Well-Being: Network of Physical Activity Assessment (INTERLIVE) is a joint European initiative of six universities and one industrial partner. The consortium was founded in 2019 and strives towards developing best-practice recommendations for evaluating the validity of consumer wearables and smartphones. This expert statement presents a best-practice validation protocol for consumer wearables assessing HR by PPG. The recommendations were developed through the following multi-stage process: (1) a systematic literature review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, (2) an unstructured review of the wider literature pertaining to factors that may introduce bias during the validation of these devices and (3) evidence-informed expert opinions of the INTERLIVE Network. A total of 44 articles were deemed eligible and retrieved through our systematic literature review. Based on these studies, a wider literature review and our evidence-informed expert opinions, we propose a validation framework with standardised recommendations using six domains: considerations for the target population, criterion measure, index measure, testing conditions, data processing and the statistical analysis. As such, this paper presents recommendations to standardise the validity testing and reporting of PPG-based HR wearables used by consumers. Moreover, checklists are provided to guide the validation protocol development and reporting. This will ensure that manufacturers, consumers, healthcare providers and researchers use wearables safely and to its full potential.Private Stiftung Ewald Marquardt fur Wissenschaft und Technik, Kunst und KulturResearch Council of Norway 249932/F20TrygFonden 310081Portuguese Foundation for Science and Technology SFRH/BPD/115977/2016MINECO/FEDER DEP2016-79512-RUniversity of Granada, Plan Propio de Investigacion 2016, Excellence actions: Units of ExcellenceScientific Excellence Unit on Exercise and Health (UCEES)European Commission SOMM17/6107/UGRScience Foundation IrelandEuropean Commission 12/RC/2289_P2European Research Council (ERC) European Commission 716657Huawei TechnologiesJunta de Andaluci