Study Overview
Objective. To assess whether systolic blood pressure improved with expert-driven or user-driven e-counseling compared with control intervention in patients with hypertension over a 4-month period.
Design. Three–parallel group, double-blind randomized controlled trial.
Setting and participants. In Toronto, Canada, participants were recruited through the Heart and Stroke Foundation heart disease risk assessment website, as well as posters at University Health Network facilities. Participants diagnosed with stage 1 or 2 hypertension (systolic blood pressure [SBP] = 140–180 mm Hg, diastolic blood pressure [DBP] = 90–110 mm Hg) and between the ages of 35 and 74 years were eligible. Hypertension diagnoses were confirmed with the participant’s family doctor at baseline if they were not prescribed antihypertensive medication. All participants were required to have an unchanged prescription for antihypertensive medication 42 months before enrollment. Participants prescribed antihypertensive medication were also required to have SBP ≥ 130 mm Hg or DBP ≥ 85 mm Hg in order to prevent “floor effects.” Exclusion criteria included: diagnosis of kidney disease, major psychiatric illness (eg, psychosis), alcohol or drug dependence in the previous year, pregnancy, and sleep apnea.
Participants were randomly assigned to 1 of 3 intervention groups: control, expert-driven, and user-driven e-counseling. Randomization was conducted by a web-based program using randomly permuted blocks. The randomization code was known only to the research coordinator and not to the investigators or research assistants who administered the assessments.
Intervention. Briefly, user-driven e-counseling enabled the participants to set their own goals or to select the interventions used to reach their behavioral goal. The user-driven group received weekly e-mails that enabled participants to select their areas of lifestyle change using text and video web links embedded in the e-mail. Expert-driven e-counseling involved prescribed specific changes for lifestyle behavior, which were intended to facilitate adherence to behavior change. Participants in the expert-driven group received the same hypertension management recommendations for lifestyle change as the user-driven group; however, the weekly e-mails consisted of predetermined exercise and dietary goals. The control group received weekly e-mails provided by the Heart and Stroke Foundation e-Health program that contained a brief newsletter article regarding BP management through lifestyle changes. The control group was distinct from the intervention groups, as the e-mails were limited to general information on BP management. Blinding to group assignment was maintained during baseline and 4-month follow-up.
Main outcome measures. The primary outcome was SDP; secondary outcomes included DBP, pulse pressure (PP), total cholesterol, 10-year Framingham cardiovascular risk (10-year CVD risk), daily physical activity, and dietary habits. Anthropometric characteristics, medical history, medication information, resting BP, daily step count, dietary behavior, participants’ readiness for lifestyle behavior changes, and participants’ cardiovascular risk (calculated by the Framingham 10-year absolute risk) were collected during the baseline and 4-month follow-up assessment.
Baseline and 4-month follow-up assessments at the Peter Munk Cardiac Center, Toronto General Hospital, University Health Network were scheduled between 8 AM and 12 PM to minimize diurnal BP variability. All participants fasted for 12 hours prior to their assessment in order to obtain accurate samples of cholesterol. Participants were also instructed to avoid smoking for > 4 hours, caffeine for 12 hours, and strenuous exercise for 24 hours prior to their assessment.
BP was measured by a validated protocol for automated BP assessments with the BpTRU blood pressure recording device. Participants were seated for >5 minutes prior to activation of the BpTRU device. The BP cuff was applied to participants’ left arms by a trained research assistant. Following the initial BP measurement, the research assistant exited the room while the BpTRU device completed an automated series of 5 BP recordings with 1-minute intervals separating each of these recordings. The recorded BP at each assessment interval was the mean of these 5 BpTRU measurements. PP was determined by the difference between SBP and DBP readings.
Daily physical activity was defined as the mean 4-day steps (3 weekdays, 1 weekend day) recorded on a pedometer (XL-18CN Activity Monitor), which all participants were given to use as part of the study. Diet was measured as adherence to recommended guidelines for daily intake of fruits and vegetables, and evaluated by the validated NIH/National Cancer Institute Diet History Questionnaire. Readiness for exercise and dietary change were measured using a questionnaire from the authors’ previous trial and the stages of change were defined as the following: precontemplation (not ready to adhere to the target behavior in the next 6 months), contemplation (ready to adhere to the target behavior in the next 6 months), preparation (ready to adhere to the target behavior in the next 4 weeks), action (adherence to the behavior but for < 6 months), and maintenance (adherence to the behavior for ≥ 6 months).
For the primary outcome (SBP), the difference among groups was evaluated using univariate linear regression. Post-hoc comparisons with Bonferroni adjustment, among the three treatment groups were performed only if the overall F-test was significant. Secondary outcomes (DBP, PP, total cholesterol, 10-year CVD risk, daily steps, and daily fruit and vegetable consumption) followed a similar statistical approach as the primary outcome analysis. Statistical significance was defined by a two-tailed test with a P value < 0.05.
Main results. Of those screened (n = 847), 128 participants were randomized into the study. Between the 3 groups (control with n = 43, user-driven with n = 42, expert-driven with n = 43), there were no statistically significant differences in age, sex, household income, education, ethnicity, body mass index, and medications (antihypertensive and lipid-lowering) at baseline. The average age was 56.9 ± 0.8 years, 48% were female, 66% had a household income of > $60,000, 79% had a college/university or graduate school education, 73% identified as white, and over 85% were taking ≥ 1 antihypertensive medications. Baseline SBP, DBP, PP, cholesterol, 10-year CVD risk, daily steps, daily vegetable intake, smoking status, readiness for exercise behavior change and readiness for dietary behavior change were also similar across the 3 groups. All participants were highly motivated at baseline for adopting a healthy lifestyle. The percentage of participants that were already in preparation, action, or maintenance of readiness for exercise and diet were 96% and 92%, respectively. Only 4% and 8% of participants were in either precontemplation or contemplation stage of readiness at baseline for exercise and diet, respectively.
The expert-driven group showed a greater SBP decrease than controls at follow-up (mean difference between expert-driven versus control: −7.5 mm Hg, 95% CI −12.5 to −2.6, P = 0.001). SBP reduction did not significantly differ between user- and expert-driven (P > 0.05). DBP reduction and improvement in daily vegetable intake was not significantly different across groups. However, the expert-driven group demonstrated a significant reduction compared with controls in PP (−4.6 mm Hg, 95% CI −8.3 to −0.9, P = 0.008), cholesterol (−0.48 mmol/L, 95% CI −0.84 to −0.14, P < 0.001), and 10-year CVD risk (−3.3%, 95% C −5.0 to −1.5, P = 0.005). The expert-driven group showed a significantly greater improvement than both controls and the user-driven group in daily steps (expert versus control: 2460 steps/day, 95% CI 1137–3783, P < 0.001; expert versus user: 1844 steps/day, 95% CI 512–3176, P = 0.003) and servings of fruit consumption (expert versus control: 1.5 servings/day, 95% CI 0.2–2.7, P = 0.01; expert versus user: 1.8 servings/day, 95% CI 0.8–3.2, P = 0.001).
Conclusion. Expert-driven e-counseling was more effective than control in reducing SBP, PP, cholesterol, and 10-year CVD risk at the 4-month follow-up. In addition, expert-driven e-counseling was more effective that user-driven counseling in improving daily steps and fruit intake. It may be advisable to incorporate an expert-driven e-counseling protocol in order to accommodate participants with greater motivation to change their lifestyle behaviors and improve BP.