The accuracy of self-reported blood pressure in the medication adherence improvement support app for engagement – Blood pressure (MedISAFE-BP) trial: Implications for pragmatic trials

Self-report of health conditions and behaviors is one potential strategy to increase the pace of enrollment into pragmatic clinical trials. In this study, we assessed the accuracy of self-reported poorly-controlled hypertension among adults in the community who were screened for participation in the MedISAFE-BP trial. Of individuals who self-reported poorly-controlled hypertension using the online trial enrollment platform, 64% had a systolic blood pressure less than 140 mmHg when measured at home. While we identified several characteristics associated with accurate self-report including older age (Odds Ratio [OR] 1.02 per year, 95% CI 1.01–1.03), diabetes (OR 1.59, 95% CI 1.17–2.14), and low health activation (OR 1.56 95% CI 1.17–2.07), we were unable to identify patients for whom self-reported hypertension would be a reliable method for their inclusion in a pragmatic trial.