Non-invasive Monitoring for Early Detection of Atrial Fibrillation
Condition: Atrial Fibrillation
MeSH terms: Atrial Fibrillation
Study type: Observational

Summary: 
      The aim of this project is to recognize the actual frequency of atrial fibrillation in the
      Polish population as well as to determine the independent risk factors for the occurrence of
      its clinically symptomatic and asymptomatic forms
    

Detailed description: 
      The AF Survey is a cross-sectional observational study aimed to assess the prevalence and
      control of AF and its correlation with CVD risk factors in Poland, based on a representative
      sample of adults aged 65+. The main aim of the survey is to assess the prevalence,
      detectability and control of AF, heart failure, vascular diseases, arterial hypertension,
      stroke, sedentary lifestyle, smoking, lipid disorders, metabolic syndrome, obesity and
      diabetes, as well as other factors related to CVD risk such as chronic kidney and liver
      diseases, sleeping disorders, depression and selected psychosocial factors.

      The assessment of AF prevalence with use of the monitoring system developed and validated
      during the first phase of the project, would be composed of a questionnaire, follow-up data
      sheet, blood pressure (BP) measurements and a blood sample collection.

      The survey consists of three visits to subjects' homes (day: 1; 10+/-4 days and 30+/-4 days)
      and one phone contact one year after first visit and would be performed by trained nurses.
      The monitoring system would be installed during the first visit for all patients who sign
      informed consent form and returned at the third visit one month later. The main questionnaire
      will be completed during the first visit, which included detailed questions about present
      health status and history of diseases, hospitalizations, and current medications. The
      socioeconomic part of the questionnaire included questions concerning the personal and family
      situation, economic status, household structure, leisure activities, hobbies, and social
      life. During this visit the Geriatric scale of depression evaluation will be given to the
      subject to be self-completed, and will be collected at the second visit. BP readings would be
      taken three times during each visit to the patient's home. Anthropometric measurements are
      taken twice: at visit one and visit three at the end of the ECG monitoring. Blood samples are
      taken from subjects at the second visit after 10 to 12-hour fasting. The follow-up data sheet
      would be completed at the initial visit and at the follow-up visit twelve months after
      inclusion to the survey. The fieldwork is subcontracted to a company specializing in market
      research projects for the private and public sectors. The transportation of biological
      material to the Central Laboratory has been subcontracted to a company with expertise in
      blood sample transport over long distances. Interviewers will be recruited from among
      professionally active nurses. Most of them will be social nurses working within local
      communities. All nurses participating in the survey will complete special training prepared
      for fieldwork executors of the NOMED-AF project.
    

Observational model: Case-Crossover
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        The survey was designed as a country representative study and was carried out on a sample
        of Polish residents aged ≥65 years, divided into six age groups of equal size and gender
        proportion (65-69, 70-74, 75-79, 80-84, 85-89 and 90+ years). The planned size of the
        research sample was 3,000 subjects (250 subjects for each gender and age group). Research
        participants were randomly recruited in clusters, in a stratified, proportional draw
        performed in three stages. The reason for overrepresentation of the oldest age groups was
        to allow separate analysis of data for older people.