Validation of a questionnaire in Spanish on asthma knowledge in teachers

Objective: To evaluate the reliability and validity of the Spanish version of the NewCastle Asthma Knowledge Questionnaire (NAKQ) for determining asthma knowledge in teachers.

Design and sample: A cross-sectional observational study in educational centers of A Coruña providing preschool, primary school and/or compulsory secondary education. Centers were selected by random sampling, stratified by ownership and educational level (24centers, 864teachers). A total of 537 (62.1%) teachers responded (precision, ±4%, confidence, 95%).

Measurements: Age, sex, academic training, teaching experience, personal/family history of asthma, NAKQ.

Analysis: Evaluation of internal consistency (Cronbach's alpha). Concurrent validity was determined by comparing scores of asthmatic teachers or with asthmatic relatives with teachers with no contact with asthma. Test-retest reliability was evaluated in two randomly selected centers by the kappa index, Bland-Altman method and intraclass correlation coefficient.

Results: Mean score on the NAKQ was 15.7±5.3 (median 17), correctly answering 50.6% of items. Cronbach's alpha coefficient was 0.824 (95%CI: 0.802-0.845). NAKQ score was higher in asthmatic teachers or with close asthmatic relatives (17.7±3.3) than in teachers with distant asthmatic relatives (16.1±5.4) and teachers without close contact with asthma (15.1±5.6; P<0.001). In the test-retest analysis (kappa 0.33-1), there were no differences in NAKQ score between the first and second completion (mean difference, 0.3±2.3; intraclass correlation coefficient, 0.863).

Conclusions: Scores obtained with the Spanish version of the NAKQ in teachers of Spanish school centers are reliable and valid to measure their degree of asthma knowledge.