Experiences of a National Web-Based Heart Age Calculator for Cardiovascular Disease Prevention: User Characteristics, Heart Age Results, and Behavior Change Survey (Preprint)

Abstract

BACKGROUND Heart age calculators are used around the world to engage the public in cardiovascular disease prevention. Previous reports of online use have not evaluated behavioural impact or controlled for repeat/fictitious use. OBJECTIVE This paper describes national use of the Australian heart age calculator in a more reliable sample of users. METHODS The heart age calculator was launched in 2019 by the National Heart Foundation of Australia. Heart age results were calculated for all users, and recorded for those who signed up for a heart age report and email follow-up over 10 weeks, after which a survey was conducted. CVD risk factors, heart age results and psychological/behavioural questions were analysed using descriptive statistics and Chi square tests. Open responses were thematically coded. RESULTS There were 361,044 anonymous users over five months; of which 30,279 signed up to receive a heart age report; and 1,303 completed the survey. For reports, there were more women (65.5%), the average age was 55.7 years, and most knew blood pressure levels (67.0%) but not cholesterol levels (40.5%). The average heart age result was 4.6 years older than current age, including 78.7% with older heart age. For the survey, most recalled their heart age category (68.5%), and many reported lifestyle improvements (63.0% diet, 62.1% physical activity). People with an older heart age result were more likely to report a doctor visit (51.0%). Participants indicated strong emotional responses to heart age, both positive and negative. CONCLUSIONS Most Australian users received an older heart age as per international and UK heart age tools. Heart age reports with follow-up over 10 weeks prompted strong emotional responses, high recall rates, and self-reported lifestyle change and clinical checks for over half of survey respondents. These findings are based on a more reliable user sample who were more likely to know their actual blood pressure and cholesterol values. Further research is needed to determine which program aspects are most effective to initiate and maintain lifestyle change. The results confirm high public interest in heart age tools, but additional support is needed to help users understand the results and take appropriate action.