ABSTRACT
Introduction: Hypertension remains a leading cause of disability and preventable death globally. This study tested patient use of a drug-device combination of a smartphone application (App) to record blood pressure (BP), drug (amlodipine) dose and side effects each day at home during the COVID-19 pandemic. Method(s): In this community-based trial with remote monitoring and remote medical management from the investigational site, hypertensive participants aged 18 years + with poor BP control (prior 7 day mean of 135 mmHg systolic BP or above and/ or 85 mmHg diastolic BP and above) were enrolled to intervention with open label dose titration over 14 weeks, allowing personalized dosing of liquid amlodipine (1-2mg steps from 1-10 mg daily). Those with adequate BP control after 7 day baseline recorded BP over the same period. Result(s): 205 patients were enrolled into the intervention group between October 2020 and July 2021. Dose-related wanted (BP reduction) and emergence of unwanted effect plots were produced for individual participants. Average BP in intervention fell from 141/87 to 131/81 (difference -10/6 p < 0.001) and observation from 125/77 to 124/76 (difference -2/1 p < 0.001). Even low doses of 1 or 2 mg amlodipine reduced BP, as did small increments e.g. from 5mg to 6 mg or from 6mg to 8mg. Mean amlodipine dose at study end averaged 5.5mg on those without amlodipine at baseline, and 7.9mg in those starting at 5mg at baseline. Adherence with participant completion of the daily App routines was high and unrelated to age (median >90%). Conclusion(s): Remote clinician assessment of twice daily home BP measurements and side effects recorded in the App may inform more precise amlodipine titration and BP control. Personalised dose-response curves for both wanted and unwanted effects may change the relationship of participant and clinician to dose selection, convincement and help optimize long term care.