Validation of questionnaire used in epidemiological blood pressure studies

Background: Standardized questionnaires add validity to the results of research as well as allow comparison with other authors' results. The aim of the study was to present the procedure and the results of the validation of authors' own questionnaire that was used as a research tool in cross-sectional epidemiological studies of the arterial blood pressure of school children. Methods: The study was carried out twice in May 2008 on a drawn group of 100 respondents-parents of primary school children. The time gap between the first test and the retest was 7 days in accordance with arbitrary criteria used in the assessment of research tool validity. Only those variables that can be presented as a dichotomy, e.g. yes or no, were validated. Kappa statistics was utilized for the assessment of individual question's repeatability. Results: Out of the total of 35 validated questions, 100% repeatability was achieved for as many as 22 questions while more than 97% for 10. The repeatability assessed by Kappa statistics could be calculated for 25 questions. Conclusion: The results indicate the questions' repeatability was very good or good. The questionnaire applied in cross-sectional research of arterial pressure can be considered reliable.