- Major progresses were made beyond the state of the art in the highly innovative data collection that was implemented. A strength of the project is that it systematically relied on objective measurement approaches for the assessment of exposures, confounders, and health outcomes. The protocol used passive sensors of location, behaviour, environmental conditions, and health (GPS receivers, accelerometers, air pollution and noise sensors, heart rate monitors, and ambulatory blood pressure monitors) and active monitors requiring an action of the subject (blood pressure at rest and spirometry). The use of some of these monitors is extremely innovative: the recently developed ambulatory blood pressure monitor that was used (TensioMed Arteriograph) measures central blood pressure (which is more predictive of target organ damage than brachial blood pressure) and aortic pulse wave velocity and the augmentation index as markers of arterial stiffness; the BioPatch has allowed us to assess heart rate variability but also accelerometry and the respiratory rate; and no study had relied on a repeated smartphone survey to assess respiratory symptoms as close as possible from their onset. A particularly innovative aspect of the project was also the simultaneous monitoring of air pollution and noise with personal monitors, as almost no study had done.
- A second measurement strength of the project, integrating methodologies from Public health and Transport sciences, was related to the precise measurement of personal transport behaviour over 6 days using GPS receivers and a GPS data-based electronic survey of visited places, trips, and transport modes. This approach allowed us to decompose in a precise way the 6-day follow-up period into time spent at the different visited places and trips and trip stages (segments of trips with a unique mode), permitting to ascribe the data collected with the behavioural, environmental, and health sensors to each trip or visited place time segment of the mobility survey.
- Progresses of the project beyond the state of the art is that with these data we have been able to document the personal exposure to air pollutants and noise according to the different transport modes at an unprecedented level of accuracy and using data from a very large number of trips made by participants from all the Grand Paris area. Other progresses accomplished so far are that we were able to accurately explore the relationship between the exposure to air pollutants (either single pollutants or cocktails or mixtures of air pollutants, taking into account inhaled quantities and not only concentrations) and the acute blood pressure response. With its sensor-based accurate data, MobiliSense provides high quality and novel information on this topic. Given the massive amount of data that we still have to analyze, other innovative findings on the health effects of transport exposures will be produced in the coming months and years.
- Finally, we have continued to develop algorithms for the smart recognition of transport, which is critical for the future assessment of transport effects on health, and critical for various disciplines that have interest in mobility (geography, urban planning, physical activity science, behavioral social sciences, etc.). A progress beyond the state of the art will be to integrate the new algorithms that we have developed during the project for the automatic recognition of mobility, trips, and transport modes into a smartphone application dedicated to collecting data in studies. We intend to apply to Proof of concept funding to expand and finalize this innovative work.
