Table 1.

The comparison of the two phases.

	Phase 1	Phase 2	Rationale for change
Components	An exploratory randomized controlled trial + qualitative interviews.	Same as phase 1.	N/A
Duration	30 days for each participants.	Same as phase 1.	N/A
Baseline data collection	A paper-based questionnaire with 23 items.	The same questionnaire was created in REDCap (http://www.project-redcap.org) a secure, web-based application. A hyperlink of the questionnaire was sent to participants on WeChat.	Completing the paper-based questionnaire at hospital was not convenient for many participants. A hyperlink sent to WeChat provided participants more flexible time. Participants could complete the survey at anytime when they were free.
Reminder	Participants in the experimental group received a reminder for every dose of medication.	Participants in the experimental group received a daily reminder.	In China, participants had the right to decide when to take each dose of their medications, although the frequency of each medication was prescribed by physicians. Because of this reason, many participants could not tell the researchers when they were going to take their medications at the enrollment.
Educational materials	All participants received them every two days at a random time between 8am and 10pm.	All participants received them every five days at a random time between 9am and 9pm.	Receiving educational materials every other day is too frequent for elderly participants to digest the included knowledge. Also, 10pm is a little bit late for many elderly participants to read educational materials.
Medication adherence measurement	The number of dosage taken divided by the number of dosage prescribed (percentage).	A standardized three-question scale named Voils Medication Non-Adherence Extent Scale (thereinafter named Voils scale).	Some participants forgot the number of dosage they taken, and others might lie about the number of dosages they taken.
Medication adherence collection	Participants reported every 3 days on WeChat. Researchers documented the data on paper.	The Voils scale was created in REDCap. A hyperlink of it was sent to participants on WeChat every 15 days. Participants reported medication adherence by clicking the hyperlink and filling the scale.	Reporting every 3 days is too frequent for many participants.
Health outcomes collection	Participants reported every 3 days on WeChat. Researchers documented the data on paper.	Within the Voils scale hyperlink, participants were asked to report their health outcomes. Participants reported them by clicking the hyperlink and filling SBP, DBP, and HR.	Reporting every 3 days is too frequent for many participants.
Interview	An interview invitation sent to the participants in the experimental group. Those who accepted were interviewed by phone call.	An interview invitation sent to all participants. Those who accepted were interviewed by phone call.	Given the small sample size, the research team wanted to hear feedback from participants.