The atrial fibrillation knowledge scale: development, validation and results

Background: Patients' understanding of the nature and consequences of atrial fibrillation (AF) and appropriate therapy, is essential to optimize AF management. Currently, no valid instrument exists to measure knowledge in AF patients with a combined focus on disease, symptom recognition and therapy. Since there is a need for a specific instrument to detect gaps in the knowledge of AF patients, we developed and assessed the AF knowledge scale.

Methods: The scale was developed based on a standard questionnaire in AF and existing knowledge scales in heart failure. Content validity was evaluated by a panel of 24 cardiology nurses, and 2 cardiologists. Face validity was assessed by judgment of 8 randomly selected AF patients, and construct validity was determined by performing an exploratory factor analysis with varimax rotation, based on 529 patients who completed the AF knowledge scale after one year follow-up. Internal consistency was calculated by means of Cronbach's α. Finally the scale was tested for sensitivity, in terms of ability to distinguish patients' knowledge levels.

Results: The scale consists of 11 items concerning AF in general, symptom recognition, and treatment. Content-, face- and construct validity appeared to be acceptable. Cronbach's α was .58. The scale was able to differentiate between knowledge levels in patients with newly detected AF and after one year follow up.

Conclusion: The instrument is valid and able to distinguish knowledge levels in AF patients. Furthermore, it can be successfully used in an outpatient care setting as an important tool in the tailoring of patient education (Clinicaltrials.gov identifier: NCT00753259).