Fiabilidad y validez externa de un cuestionario de conocimiento sobre riesgo y enfermedad cardiovascular en pacientes que acuden a farmacias comunitarias de España

OBJECTIVES: To determine the test-retest reliability of a questionnaire, with a validation preliminary, to assess knowledge of cardiovascular risk (CVR) and cardiovascular disease in patients attending community pharmacies in Spain. To complement the external validity, establishing the relationship between an educational activity and the increase in knowledge about CVR and cardiovascular disease. DESIGN: Sub-analysis of a controlled clinical study, EMDADER-CV, in which a questionnaire about knowledge concerning CVR was applied at 4 different times. LOCATION: Spanish Community Pharmacies. PARTICIPANTS: There were 323 patients in the control group, from the 640 who completed the study. MAIN MEASUREMENTS: Intraclass correlation coefficient to assess the reliability in 3 comparisons (post-educational activity with week 16, post-educational activity with week 32, and week 16 with week 32); and the non-parametric Friedman test to establish the relationship between an oral and written educational activity with increasing knowledge. RESULTS: For the 323 patients in the 3 comparisons, the intraclass correlation coefficient values were 0.624; 0.608 and 0.801, respectively (fair-good to excellent reliability). So, the Friedman test showed a statistically significant relationship between educational activity and increased knowledge (p < .0001). CONCLUSIONS: According to the intraclass correlation coefficient, the questionnaire aimed at assessing the knowledge on CVR and cardiovascular disease has a reliability between acceptable and excellent, which added to the previous validation, shows that the instrument meets the criteria of validity and reliability. Furthermore, the questionnaire showed the ability to relate an increase in knowledge with an educational intervention, feature that complements its external validity.