JMIR Publications

ABSTRACT

Background:

Identifying high-risk individuals is crucial for prevention of cardiovascular diseases (CVD). Currently, risk assessment is mostly performed by physicians. Mobile health (mHealth) applications could help to decouple the determination of risk from medical resources by allowing unrestricted self-assessment. Respective test results need to be interpretable for laypersons.

Objective:

Together with a patient organization, we designed a digital risk calculator that allows people to individually assess and optimize their CVD risk. The risk calculator is integrated into the mHealth app HerzFit, which provides respective background information.

Methods:

In order to cover a broad spectrum of individuals in both primary and secondary prevention we integrated respective scores (Framingham 10-year CVD, SCORE2, SCORE2-OP, and SMART) into a single risk calculator that was recalibrated for the German population. In primary prevention, an individual heart age is estimated which gives the user an easy-to-understand metric for assessing cardiac health. In secondary prevention the risk of recurrence is assessed. In addition, a comparison of expected to mean and optimal risk levels is determined. The risk calculator is available free of charge. Data safety is ensured by processing the data locally on the users´ smartphones.

Results:

Offering a risk calculator to the general population required utilization of multiple instruments, as each provides only a limited spectrum in terms of age and risk distribution. Integration of four internationally recommended scores allows risk calculation from 30 to 90 years of age in individuals with and without CVD. Such integration required recalibration and harmonization to provide consistent and plausible estimates. In the first 14 months after the launch, the HerzFit calculator was downloaded more than 96.000 times, indicating a great demand. Public information campaigns proved effective in publicizing the risk calculator and contributed significantly to the download numbers.

Conclusions:

The HerzFit calculator opens up CVD risk assessment to the general population. The public demonstrated a large demand for such risk calculator as it was downloaded up to 10,000 per month, depending on campaigns creating awareness for the instrument.