Effect of Digital Technologies on Risk Factor Modification
Condition: Coronary Artery Disease
MeSH terms: Coronary Artery Disease
Study type: Interventional

Summary: 
      DigTech investigates the effect of a text message-based intervention to encourage lifestyle
      change on objective measures of cardiovascular risk in individuals with coronary heart
      disease (CHD) after percutaneous coronary intervention (PCI).

      DigTech will recruit 700 participants from 18-75 years old with CHD after PCI. Half of the
      participants will be randomised into a 24 week intervention trial, which includes sending 4
      personalized short messages about risk factors modification 4 times per week and the other
      half will be controls.

      Participants will complete 3 main study visits:

        -  Visit 1: Baseline visit conducted at the beginning of the study

        -  Visit 2: Randomization

        -  Visit 3: End of study (24 weeks). Each visit will repeat the same set of cardiovascular
           measures including information about previous treatment, blood pressure, ECG,
           echocardiography, stress tests, blood sampling, International Physical Activity
           Questionnaires (IPAQ) and other measures.
    

Detailed description: 
      DESIGN: DigTech is a parallel-group, single-blind, randomized clinical trial investigating
      the changes in cardiovascular risk factors (low-density lipoprotein cholesterol [LDL-C]
      level, blood pressure, body mass index [BMI]) according to personalized intervention, based
      on individual short messages in CHD patients after PCI.

      BACKGROUND AND AIMS:

      Cardiovascular disease prevention, including lifestyle modification, is important but
      underutilized. Mobile health strategies could address this gap but lack evidence of
      therapeutic benefit.

      This trial aims at the examination of the effect of a lifestyle-focused personalized support
      program delivered by mobile phone text message on cardiovascular risk factors.

      PARTICIPANTS: 700 participants aged 18-75 with CHD after PCI.

      RECRUITMENT: Tyumen Cardiology Research Center, branch of the Tomsk NRMC

      CONFIDENTIALITY: All information and documents collected will be stored securely and kept in
      strict confidence in compliance with regulatory acts.

      Study samples, investigation results and incidental findings. The use of the participants'
      study samples and investigations are clearly defined in the participant information leaflet
      and will be explained during the informed consent process.

      CONSIDERATION OF NULL HYPOTHESES: A null hypotheses that personalized lifestyle intervention
      based on received 4 text messages per week for 6 months in addition to usual care in CHD
      patients after PCI does not reduce LDL-C levels, blood pressure and BMI" was not selected.

      SAMPLE SIZE SELECTION: Prior study shows that a sample size of 634, increasing to 704 to
      allow for a10% loss to follow-up, would have 90% power (2-tailed and at a 5% significance
      level) to detect a difference of 10 mg/dL in LDL-C level.

      INTERVENTION: The text message will be based on the prevention program involved delivery of
      regular personalized text messages (some messages personally addressed through a
      "mail-merge"-type function with the participant's preferred name) providing advice,
      motivation, and information that is aimed to improve diet, increase physical activity, and
      encourage smoking cessation (if relevant). Content for each participant will be selected
      using a re-specified algorithm dependent on key baseline characteristics. Participants will
      receive 4 messages per week for 24 weeks. Each message will be sent on 4 of 5 randomly
      selected days and arrived at random times of the day during working hours. The content of
      messages will be based on national guidelines on cardiovascular disease prevention.

      STUDY PROCEDURES AND DATA COLLECTION

      SCREENING VISITS: Screening Visit Procedures (Visit 0). Evaluation of inclusion and exclusion
      criteria. Patients will provide written informed consent on this visit.

      MAIN STUDY VISITS COMPLETION OF STUDY VISITS 1-3

      There are three main visits planned for each participant:

      Visit 1: conducted at the beginning of trial (baseline).

        -  Questionnaire. It will collect detailed information about physical activities
           (International Physical Activity Questionnaires short form) and also lifestyle
           information such as daily routines and use of alcohol and tobacco, information about
           previous treatment.

        -  Physical Measures. Investigators will measure blood pressure, height, weight, BMI, heart
           rate.

        -  Cardiovascular Measures:

             1. Electrocardiogram (ECG).

             2. Echocardiogram

             3. Six Minute Walk Test.

             4. Coronary angiography

        -  Blood Sampling including blood lipid spectrum (total cholesterol, triglycerides,
           cholesterol high-density lipoproteins and cholesterol low-density lipoproteins). Fasting
           blood samples will be analyzed by local laboratories.

      Visit 2: Randomization. Randomization will be performed after PCI, prior to discharge from
      the hospital.

      Randomization will occur via a computerized randomization program that will access through a
      secure web interface. The random allocation sequence will be in a uniform 1:1 and will be
      concealed from study personnel. Study staff will enroll patients by entering data into the
      secure web interface. The computerized randomization program interfaced with the
      message-sending program to trigger the sending of messages to patients randomized to the
      intervention. To maintain blinding of personnel study, patients will be informed of their
      allocation in a text message sent after hospital discharge. Prior to their follow-up
      appointment patients also will receive a text message to ask them not to reveal their
      allocation status to study personnel or clinicians in follow-up visits. Intervention
      participants will receive, in addition to usual care, the 6-months prevention program of
      approximately 96 messages. Control participants will receive usual care, which generally
      included community follow-up with the majority referred to inpatient cardiac rehabilitation,
      as determined by their usual physicians.

      Visit 3: conducted after 24 weeks (at the end of the trial, Follow-up visit).

      ANALYSIS: Patient demographic characteristics and other baseline information will be
      summarised by treatment group. Numbers (with percentages) for binary and categorical
      variables and mean (standard deviation), or median (interquartile or full range) for
      continuous variables will be presented. Normality of variables will be assessed by visual
      assessment of the normality curves and the Kolmogorov-Smirnov test. The analysis of the
      primary outcome will be assessed using analysis of covariance (ANCOVA) adjusting for baseline
      values and minimisation factors used in the randomisation process. Results will be presented
      as adjusted mean difference in change in ambulatory blood pressure between randomised groups
      at 4 months with 95% confidence intervals (CI) and associated two-sided p value. The above
      method was also used for continuous secondary outcomes. With respect to management of
      combined risk factors, the proportion of patients achieving control of risk factors was
      analyzed in terms of relative risk at month 6 and compared between groups using a
      log-binomial regression. If the model assumptions are not met and evidence of departure from
      Normality is observed, transformations of the data will be employed or non-parametric tests
      will be carried out. Statistical analysis will be carried out using SPSS statistical
      software.
    

Intervention name(s): Digital technology
Intervention type(s): Behavioral
Intervention description(s): Lifestyle-Focused Text Messaging
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Prevention