User experience of instant blood pressure: exploring reasons for the popularity of an inaccurate mobile health app

Abstract

Instant blood pressure (IBP) is a top-selling yet inaccurate blood pressure (BP)-measuring app that underreports elevated BP. Its iTunes app store user ratings and reviews were generally positive. Whether underreporting of elevated BP improves user experience is unknown. Participants enrolled at five clinics estimated their BP, measured their BP with IBP, then completed a user experience survey. Participants were grouped based on how their IBP BP measurements compared to their estimated BP (IBP Lower, IBP Similar, or IBP Higher). Logistic regressions compared odds of rating "agree" or "strongly agree" on survey questions by group. Most participants enjoyed using the app. In the adjusted model, IBP Higher had significantly lower proportions reporting enjoyment and motivation to check BP in the future than IBP Similar. All three groups were comparable in perceived accuracy of IBP and most participants perceived it to be accurate. However, user enjoyment and likelihood of future BP monitoring were negatively associated with higher-than-expected reported systolic BP. These data suggest reassuring app results from an inaccurate BP-measuring app may have improved user experience, which may have led to more positive user reviews and greater sales. Systematic underreporting of elevated BPs may have been a contributor to the app's success. Further studies are needed to confirm whether falsely reassuring output from other mobile health apps improve user experience and drives uptake.

Keywords: Epidemiology; Hypertension.

Fig. 1

Distribution of survey responses and survey prompts

Fig. 2

Proportion rating “agree” or “strongly agree” for each domain in the survey, unadjusted and adjusted models*. *The bars indicate a 95% confidence interval surrounding the point estimate of proportions. The adjusted model accounts for age, sex, race, level of education, history of hypertension, receipt of antihypertensives, smartphone ownership, and history of mHealth app ownership. Proportions were converted from odds and were not bounded to 100%. Two stars indicates that the IBP Similar group is significantly different from the IBP Higher group. Three stars indicates that the IBP Lower group is significantly different from the IBP Higher group

Fig. 3

Study flow of the IBP validation study and visualization of group definitions*. *Panel A depicts the flow of the complete IBP validation study. The present analysis was a preplanned substudy embedded within the IBP validation study. Results from the standard device measurement was not incorporated into the present analysis as participants were blinded to the results until they completed the user experience survey. Panel B visually depicts the group definitions and percentage of all in each group