[The Spanish version of the Newcastle Asthma Knowledge Questionnaire for parents of children with asthma (NAKQ). Transcultural adaptation and reliability analysis].
INTRODUCTION
The Newcastle Asthma Knowledge Questionnaire for parents of children with asthma (NAKQ) has proven to be a valid instrument for asthma knowledge assessment of patients and their parents. The widespread use of the SRS-22 in non-English-speaking countries requires its transcultural adaptation. Our objective was to obtain a version of the NAKQ questionnaire adapted to Spanish and to analyze its validity and reliability.


MATERIAL AND METHODS
The Spanish version was obtained by using the forward/back-translation method with expert, bilingual translators. The questionnaire was administered to 157 parents with high knowledge (n = 78) and low knowledge (n = 79) of asthma. The differences in the number of answers between both groups were analyzed with the chi(2) test. Internal consistency was determined with Cronbach's alpha coefficient and test-retest reliability with the tau-b of Kendall correlation coefficient, and kappa statistics.


RESULTS
At the end of the process, 23 of the 31 items were classified as of total equivalence and eight ase of moderate equivalence. The mean score of parents high knowledge was 23 +/- 2.94 and the mean score of parents low knowledge was 16.84 +/- 2.56. The difference between the two groups was statistically significant (p < 0.001). The overall Cronbach's alpha coefficient of the questionnaire was 0.72, the Kendall's tau-b 0,8573 was significant (p = 0.01) and the kappa index showed good or very good consistency in more than half of the items.


CONCLUSIONS
The Spanish version of the NAKQ has proven to be acceptable and culturally equivalent to the original version and it has a good degree of consistency, validity and reliability.