Study design
This was a randomized, controlled clinical trial (IRCT2015111712211N2) with two parallel arms designed to demonstrate the effect of BPMAP (Supplementaryfile1) on self-management of hypertensive patients in adherence to the treatment and control of hypertension risk factors (19). This article was written using the CONSORT 2010 checklist (See additional file 1).
Study setting
The ‘Tehran Heart Center’ is a tertiary-referral cardiovascular subspecialty medical center affiliated to ‘Tehran University of Medical Sciences’ in Iran. each year, The center has about 113,000 outpatients, 24,000 admissions, and performs 4,000 open heart surgeries (20).
Participants
The participants included patients with primary hypertension diagnosed and confirmed by their physician. Inclusion criteria were, 30-60-year-olds, being literate (at least primary education), being treated for hypertension (ICD code: I10) for at least one year, possession of and the ability to use a smartphone, willingness to participate in the study, and residence in the study region throughout the study period. Exclusion criteria were, complications of hypertension such as myocardial infarction (I22), stroke (I64), other cardiovascular diseases (I51.6), diabetes (E10-E14), and physical disability (Z73.6).
Interventions
Participants in the intervention group received a mobile application-based educational-supportive intervention, along with the routine treatment. The content and features of the application were prepared based on the educational needs of hypertensive patients(21). The application had the following features; a) recording blood pressure and receiving feedback of the recorded blood pressure, b) saving the recorded blood pressure levels and plotting them as a chart, c) reminding the time of drug consumption, visit date, and blood pressure measurement, d) healthy diet(DASH and low-salt diet) and weight loss plans, e) knowledge-based information on the nature, control, and treatment of the disease, f) motivational and supportive programs for smoking cessation, g) sending notifications or informing one of the patient’s family members of critical blood pressure levels, h) sending general motivational messages and reminders about adherence to treatment to all patients and specific individual messages based on patient characteristics, and i ) saving the recorded information by users on the portal for physicians and researchers.
Participants in the comparison arm received the usual care, including, taking their medical history, undergoing physical examinations, such as, measurement of blood pressure and weight, laboratory tests and paraclinical services tailored to the individuals’ conditions, and drug treatments according to the JNC8 (22), recommendations.
Outcomes (Primary and secondary)
Adherence to antihypertensive medication was considered as the primary outcome, assessed with the 14-item Hill-Bone Scale (23). The secondary outcomes included clinical and behavioral outcomes, such as adherence to the DASH diet, reduced sodium and fat intake, regular blood pressure monitoring, physical activity, predisposing, enabling, and reinforcing factors in adherence to treatment. Clinical outcomes were measured by a physician and other outcomes were measured by a questionnaire. The questionnaire was completed by a trained researcher.
Adherence to the DASH diet and sodium reduction: The intake of salt, fat, low-fat dairy products, fruits, and vegetables over the past week was evaluated.
Regular blood pressure monitoring: The frequency of blood pressure in the application was recorded in the study period.
Physical Activity: The degree of change in the frequency and time allocated to physical activity was evaluated in two categories of moderate and severe physical activity.
Predisposing, enabling, and reinforcing factors in adherence to treatment: The effect of these factors was evaluated based on the questionnaire items.
Sample size
We calculated that a total of 120 people (60 in each group)would be needed to achieve a power of 80 (1-β) to detect at least a 5-score (SD= 10) difference on the Hill-Bone Compliance to high blood pressure scale (23) using the two-sided T-test at the significance level of 5% (α).
Randomization
After eligibility screening, using random sequence which was generated by online randomization (www.sealedenvelope.com) in advance, we assigned the eligible subjects to two groups. The random sequence was generated using permuted block randomization with block size of four and 1:1 allocation ratio.
Implementation
Individuals were given one week to review and consult with the family to read and sign the informed consent form. After the participants signed the informed consent, the initial assessment questionnaire was completed by a trained interviewer (Fig. 1). The application was installed on the mobile phones of the intervention group and instructions were provided to the patients individually.
Blood pressure was measured by the “WELCH ALLYN Tycos Jewel Movement Sphygmomanometer” at the clinic. The patients’ sphygmomanometers were calibrated at the time of application installation to ensure correct measurement of blood pressure at home.
Follow-up assessments
Participants in both groups had an initial visit and six follow-up visits. The first 5 visits were performed with a two-week interval and the last one 24weeks after the first visit (Table 1). In both groups, clinical evaluation and the questionnaire completion were done at baseline, eight weeks after receiving the application, and at the 24thweek.
Data collection methods
The primary outcome was measured by the Hill-Bone Scale and secondary outcomes by a mercury sphygmomanometer and the researcher-made questionnaire.
The questionnaire contained patients’ demographic information, treatment status, some health-related behaviors as the initial assessment. A number of the PRECEDE (Predisposing, Reinforcing and Enabling Constructs in Educational Diagnosis and Evaluation) model constructs (predisposing, enabling, and reinforcing factors), the World Health Organization STEPS questionnaire for monitoring chronic risk factors, (13), the Hill-Bone Compliance Scale, and the Global Physical Activity Questionnaire (GPAQ) guide were used in its design(24). It contained 68 questions for assessing 6 domains. The domains and the number of questions in each are as follows: a) Physical and biochemical measurements (9), b) Assessment of disease history (7), c) Assessment of health behaviors smoking (4); nutritional diet (5); physical activity (6), d) predisposing (18)- enabling (2)- and reinforcing factors (3) of adherence, e) Hill-Bone adherence to treatment questionnaire (14). The questions in domain ‘c’ have been taken from the STEPS and the GPAQ questionnaires.
Data management
The patients’ data were obtained from the self-report questionnaire and the application. Whenever the users would go online, their activity in the application would be stored on the portal (Supplementary file 2, table 1). The final databank was prepared in SPSS 20.0. A double entry was made to ensure that the data was entered correctly. In the event of any discrepancy, the information entered was verified with the initial data.
Statistical methods
The baseline characteristics of patients in the two treatment groups were reported using mean (standard deviation) for quantitative variables (age, cholesterol, blood pressure, weight, adherence parameters, …) and frequency (frequency percentage) for qualitative variables (sex, marital status, education, frequency of BP measurement, …).
To analyze the effectiveness of the main variable outcomes, we used repeated measurement analysis of covariance (general linear model) to compare the mean change of interested variables) adjusted to the baseline score at a confidence interval of 95 %. We set the intervention group as the fixed and the times of measurement as the repeated factors. All analyses were conducted using SPSS (version 20.0).