The MyHeart Counts cardiovascular Health Study Netherlands

The study of determinants of cardiovascular disease (CVD) is important because
it provides insight in risks and opportunities to reduce the burden of CVD. A
major gap in our current knowledge about CVD lies in the way we measure these
determinants, for example physical activity. This is currently restricted to
paper questionnaires and short-duration measurements. Here lies the potential
for smartphone technology. The ResearchKit MyHeart Counts app allows
researchers to collect data continuously and in large populations.
Addutionally, in-app coaching could stimulate a healthy lifestyle. However, the
effect of different coaching levels on a smartphone is not yet known. The
MyHeart Counts app has been released successfully in the USA by Stanford
University. However, the effect and feasibility of this method for use in the
Netherlands has not been established.

The primary aim is to assess the effectiveness of four coaching interventions
in increasing daily activity of MyHeart Counts app users.

Secondary aims are 1) to study the feasibility (technical, legal and ethical,
data quality, costs) of the MyHeart Counts app in the Dutch ambulatory
population 2) to study the associations of determinants (Diet, Smoking,
Well-being, Risk perception of cardiovascular disease, Physical activity,
Sleep) of cardiovascular disease with self-reported cardiovascular health and
3) Subgroup analysis of primary endpoint. Test whether a particular cluster of
individuals will respond more or less favourably to a particular prompt.

app-based observational study with integrated cross-over trial

four different coaching levels

The observational study consists of 7-day study periods, with a frequency of
one study period per three months. During these study periods participants will
be asked to answer in-app questionnaires and perform a 6-minute walk test with
their smartphone at the end of the week. After the first study period,
participants are randomized to four different coaching levels in four
subsequent weeks. In total, the study takes 5-10 minutes per day in the first
week, and 1-2 minutes per day in the following four weeks. The total study
takes 5 weeks. Participating with this research does not carry extra health
risks. Benefits for participants include getting insight in their
cardiovascular risk, personal lifestyle coaching and easy contribution to
cardiovascular research from their smartphone.