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.


METHODS



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.