Intervention ingredients and tailoring
Overall framework
As shown in Figure 1, PHMA aims at preventing and reducing hypertension harms by eight objective behaviors including: a) attending and responding to project messages/ contacts; b) performing self-monitoring and reporting; c) modifying unhealthy diet habits or practices; d) maintaining adequate physical exercise/activities; e) containing tobacco and alcohol consumption; f) addressing emotion and sleep problems; g) using clinical checkups and treatment; and h) facilitating family engagement and support. These objective behaviors are promoted through two intervention stages and five intervention measures. More specifically, the intervention for each participating patient starts with an orientation stage followed by a problem-solving stage. The orientation stage aims at equipping the patient with essential knowledge and attitudes about each of the objective behaviors applicable and helping him/her start to practice these behaviors. While the problem solving stage facilitates the patient to identify and solve problems or barriers encountered in practicing the objective behaviors initiated in the orientation phase. The five intervention measures are: support for self- monitoring (I1), supervised machine communication (I2), daily education or reminder message (I3), weekly blood pressure notification (I4), and quarterly signed feedback (I5). Design of detailed content or procedures of these measures is guided by proven theories or strategies including system synergy [24], health belief model [25], social cognition theory [26], motivational interviewing [27], nudging strategies [28] and computerized tailoring. The following subsections briefly introduce each of the intervention measures.
Support for self-monitoring (I1)
PHMA provides necessary technical support for participant patients to facilitate their practice of the objective behaviors especially self-monitoring. First, it maintains a cloud database and web-based support system capable of receiving, storing and processing patients’ self-monitored data and allowing them to view their personal records and feedbacks. Second, the project provides each participant patient with an electronic tonometer which: allows the patient to measure point SBP, DBP and pulse at home; sends the results to a cloud data center maintained by the project; and receives and plays voice messages disseminated from the cloud center. Third, the project encourages the participating patients to log onto their personal online accounts to: view their hypertension management profile (Figure 2) and all the messages, notifications, feedbacks and other IEC (information, education and communication) materials he/she has received in the past; and administer relevant self-monitoring questionnaires (Appendix 1) as suggested.
Supervised machine communication (I2)
PHMA delivers supervised machine communication (SMC) via telephone at the beginning when the patient enrolls into the project and then at the end of every three months. The communication is conducted mainly by an AI (artificial intelligence) voice processing system according to preset transcripts but the process is supervised by a human professional to handle exceptional machine-patient interactions. SMC comprises baseline and follow-up sessions lasting for about half an hour each. The baseline SMC introduces PHMA and invites participation in the project, and, if successful, performs a brief yet comprehensive assessment of the patient’s: a) diagnosis and treatment history; b) symptoms of hypertension complications; and c) BP-related lifestyle practices. Each of the follow-up SMC session focuses primarily on the patient’s hypertension management in the past quarter and discusses: status and trends of his/her BP; efforts and progresses made in managing his/her hypertension; difficulties encountered; and plans or suggestions for overcoming the difficulties.
Daily education or reminder message (I3)
PHMA sends short (less than 120 Chinese characters), daily (once a day), and bi-modality (text and voice) messages via: a) voice electronic tonometer; and b) WeChat (the most popular social media in China), if the patient is a frequent WeChat user; or c) mobile phone, if the patient uses mobile phone but are not used to WeChat. Content of the messages differs from patient to patient and from time to time but has changing focuses depending on the actual sequence of objective behaviors to be promoted and behavior problems to be addressed. Taking the example shown in Figure 2, the “intervention focus” during weeks 16 to 32 was “C” and so all messages send to that specific patient during these weeks centered on “modifying unhealthy diet”. All the messages are purposefully kept short to minimize burden of reading/ listening and the “one message every day without stop” strategy is adopted to maintain a consistent bond with the patient and reinforce the objectives behaviors continuously.
Weekly blood pressure notification (I4)
PHMA sends a weekly notification about trends in SBP, DBP, pulse BP and BP control rate in turn for every participating patient. In other words, if a patient receives a short notification about his/her SBP at the end of this week, he/she will receive a notification about DBP, pulse BP and BP control rate at the end of the next one, two and three week(s) respectively. Then these are repeated for every four weeks. Figure 3 uses SBP as an example and illustrates how the content of the notification is generated using to the patient’s self-measured blood pressure data.
Quarterly signed feedback (I5)
PHMA disseminates quarterly feedbacks to each of its participant patients via: a) paper letter sent by postal service; b) personal webpage; and c) WeChat. Each feedback addresses a specific objective behavior first in the orientation phase or a specific barrier to implementing the objective behaviors later in the reinforcement phase. Content of the feedbacks consists five parts: a) identity and time, to indicate that the feedback is current and addressed to the specific patient named; b) BP performance, to tell the patient about his/her BP status and trend and indicate that the feedback centers on his/her BP; c) efforts made recently, to appreciate the patient’s efforts and progresses in the previous time period and identify main areas for improvement; d) actions to take next, to propose feasible actions for the patient to take in next period; and e) signatures, to tell the patient that the feedback is produced and checked by authorized professionals and thus useful and reliable. Figure 4 provides an example feedback.
Methods for tailoring interventions
PHMA uses comprehensive approaches in tailoring interventions to the need and context of individual patients. First, PHMA requires that the intervention for any specific patient in any specific time period focuses on only one most important and feasible objective behavior or behavior problem determined by a priority score. This score is automatically generated by a computerized algorithm based on data accumulated from previous SMC with the patient and his/her self-monitoring. Second, all items in the IEC materials pool of PHMA are designed as templates inserted with variables and when any of them is sent to a specific patient, the variables are replaced with relevant values, text or images according to his/her actual conditions/contexts. The following is a “template” message: “{CustomerDemographics.FullName}: Capping monthly salt intake is an effective way in controlling blood pressure. You have {CustomerDemographics. FamilyMember.Number} members living together. So, your family should consume less than {ObjectiveBehavior HealthyDiet.MonthlyFamilySalt} grams of salt a month in total.” As indicated by “{}”, this message contains three variables. When sent to a patient named “Zhang San” who have 3 family members (two adults and a child of 8 years), the message is change into: “Zhang San: Capping monthly salt intake is an effective way in controlling blood pressure. You have 3 members living together. So, your family should consume less than 180 grams of salt a month in total.” Figure 5 shows the template of the quarterly signed feedbacks mentioned earlier and Figure 4 is in fact an example feedback generated from this template.
Variables for characterizing patients
PHMA maintains a growing pool of variables for characterizing individual patients. All these variables are classified, coded and computerized in a way that they can be easily: a) added to relevant IEC templates in intervention development; and b) replaced, in intervention implementation, with relevant values, text or images according available data about the specific patients under concern. By the time this paper is written, a total of ten categories and over 300 of variables have been computerized. Table 1 presents all the categories identified so far and example variables under each category.
Study design and setting
The study adopts a cluster randomized controlled trial (RCT) design involving a total of 60 site communities with 12 in the control arm and 48 in the intervention arm. The control arm maintains existing hypertension patient management; while the intervention arms, personalized hypertension management as described earlier. Project evaluation applies to both arms using the same data collection methods and by same field data collectors. As mentioned in the “intervention tailoring” subsection above, detailed intervention varies from patient to patient due to the personalized approach. So, the uneven distribution of site communities between the control and intervention arms was designed to enable detection of potential differences between the control arm and at least four main subgroups with different intervention ingredients in the intervention arm. The analysis and reporting of the trial will be in accordance with the CONSORT guidelines [29, 30] (see Supplemental File 2 for CONSORT checklist).
Selection and randomization of communities
The RCT is implemented in Anhui, an inland province located in eastern China with a population of about 70 million living in 105 cities or counties. Selection of participating sites and patients uses a clustered randomization which proceeds in the following steps: 1) divides Anhui province into north, middle and south regions; 2) randomly select 4 cities/counties from each of the three regions; 3) randomly select five non-adjacent communities from each of the cities/counties selected; 4) randomly select 56 patients diagnosed with hypertension from the communities selected. The five communities selected from each cities/counties in steps 3 are randomly assigned to the control arm (n=1) and intervention arm (n=4). All the randomization is performed by a statistical professional from outside the project team.
Calculation of hypertension patients
The above sample size of participating patients is calculated on base of our primary intervention assessment measures, i.e., changes in systolic blood pressure (SBP). Based on our previous study results and the aim of comparing the effects of at least four subtypes of combinations of mainly intervention ingredients, we suppose: a) SBP reduction was about 5.0 mmHg as compared between the intervention and control arms; b) standard deviation of the SBP reduction was 7.8 mmHg; c) ICC value was 0.05; and d) only one out of four patients in each intention arm meets the criteria to receive the pre-assigned subtype intervention. So to detect a possible absolute difference of 5.0 mmHg with 90% power and alpha 0.05, we need 228 patients in each arm. By allowing for a 20% attrition rate and a design effect of 2.45, the total sample size is estimated as 3352 (=2.45 * 228 * 5 * 1.2) and this translates into about 56 patients per community.
Measures and data collection
The primary measures for assessing the efficacy of PHMA are SBP/DBP. The secondary measures include quality of life (EQ5D-5L), hypertension-related complications, healthcare utilization and objective behaviors. All these measures together with data about potential confounding variables (e.g., age, sex, education, years since hypertension diagnosis) are collected at the patients’ households by trained data collectors at baseline and every 12 months after baseline. SBP/DBP is measured using a mercury sphygmomanometer in accordance with standard operation specifications [31]; while the remaining data are solicited using structured questionnaires (Supplemental File 1).
Data analysis
The data collected through the above randomized controlled experiment will be used to: a) compare the differences in SBP/DBP between the control groups and the intervention group as a whole and subgroups with different intervention ingredients in the intervention arm at different time points; and b) compare the differences, again between the control and intervention/sub-intervention groups, in terms of the secondary measures including quality of life, occurrence of hypertension-related complications, healthcare utilization, and scores of objective behaviors.