This is a stepped wedge cluster randomized controlled trial design. This study aims to examine the efficacy and safety of CHM teabag in decreasing stroke risk by machine-learning-based retinal image analysis in elderly population.~A total of 912 participants will be recruited from 9 clinics. 2~3 clinics will represent a cluster unit. The stepped wedge design will consist of four groups each containing four randomly allocated cluster units, allocated to either 4, 8, 12, or 16 weeks of the intervention. The intervention is Chinese herbal teabag treatment, which will consist of five Chinese herbs (a total of 10g). The first group will receive 16 weeks of the intervention, the second group will receive 12 weeks, the third group will receive 8 weeks, and the forth group will receive 4 weeks.~The primary outcome measure is the stroke risk estimated with Automatic Retinal Image Analysis (ARIA). Secondary outcome measures include Framingham Stroke Risk Score (FSRS), cognitive impairment risk estimated with ARIA, Hong Kong version of the Montreal Cognitive Assessment (MoCA), Constitution in Chinese Medicine Questionnaire (CCMQ), World Health Organization Quality-of-Life Scale (WHOQOL-BREF), Health-promoting lifestyle profile II (HPLP-II), and adverse events.
This stepped wedge cluster randomized controlled trial aims to examine the efficacy and safety of CHM teabag in decreasing stroke risk by machine-learning-based retinal image analysis in elderly population.