Efficacy of a Brief Intervention on Reduction of Systolic Blood Pressure
Condition: Blood Pressure, High; Cardiovascular Risk Factor
MeSH terms: Hypertension; Systolic Murmurs
Study type: Interventional

Summary: 
      This study examines the efficacy of individualized counseling letters to reduce systolic
      blood pressure level of ≥ 130 mmHg in individuals aged between 40 and 65 years. The
      computer-generated counseling letter intervention aimed to increase moderate-to-vigorous
      physical activity, to reduce sedentary time, and to achieve smoking abstinence.
    

Detailed description: 
      This study examines the efficacy of individualized counseling letters to reduce systolic
      blood pressure level of ≥ 130 mmHg in individuals aged between 40 and 65 years. The
      computer-generated counseling letter intervention aimed to increase moderate-to-vigorous
      physical activity, to reduce sedentary time, and to achieve smoking abstinence. Participants
      are recruited by nurses in routine care of primary medical practices.

      Informed consent consists of: (i) participation in standardized measurement of blood pressure
      as well as waist and hip circumference at baseline and 12-month follow up, (ii) completion of
      standardized questionnaires at 4 time points (baseline, 4-month, 7-month, and 12-month
      follow-up). Participation in accelerometry was defined as an option. Individuals who agree to
      wear the accelerometer do this for 10 days at baseline and 12-month follow-up, each.

      After baseline assessment, individuals are randomly allocated to a control and to an
      intervention group (ratio 1:1).

      Intervention: The computerized intervention system includes three interactions with
      participants aiming to increase moderate-to-vigorous physical activity and to reduce
      sedentary time. For individuals who were daily smokers at baseline, the computerized
      intervention system includes three more interactions with participants aiming to foster the
      motivation to quit smoking. Recurrent assessments are initiated by the system and provide
      data for scheduling the proceeding intervention steps and selection of relevant content.
      Physical activity, sedentary time, smoking, and motivational measures to change or maintain
      behaviors according to the recommendations will be monitored over time and used to provide
      feedback in the form of letters.

      Intervention group: Individuals in this group complete a tablet PC-supported assessment at
      baseline and 12-month follow-up, both at the general practice. At months 4 and 7, follow-up
      data are collected by study team members via phone call. According to the assessments
      (baseline, month 4, and month 7), participants receive three counseling letters aiming to
      increase moderate-to-vigorous physical activity and to reduce sedentary time. Additionally,
      individuals who were daily smokers at baseline, receive three counseling letters aiming to
      foster the motivation to quit smoking. The first letter is accompanied by a self-help manual
      covering specific information relevant for the particular stage of motivation to change
      smoking behavior according to the principles of the Transtheoretical Model of behavior
      change.

      Control group: Individuals in this group complete a tablet PC-supported assessment at
      baseline and 12-month follow-up, both in the general practice. At months 4 and 7, follow-up
      data are collected by study team members via phone call.
    

Intervention name(s): Counseling letter
Intervention type(s): Behavioral
Intervention description(s): The brief counseling letter intervention aiming to reduce physical inactivity, sedentary time in leisure time as well as smoking is based on behavior change theories (Transtheoretical model of health behavior change and Health Action Process Approach).
The computerized intervention system includes up to six interactions with participants. Recurrent assessments are initiated by the system and provide data for scheduling the proceeding intervention steps and selection of relevant content. Physical activity, sedentary time, smoking, and motivational measures to change or maintain behaviors according to the recommendations will be monitored over time and used to provide feedback in the form of letters.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Prevention
Keywords: systolic blood pressure; physical activity; sedentary time; smoking