Educational intervention in farmers with occupational asthma: long-term effect on exhaled nitric oxide.

BACKGROUND The fraction of exhaled nitric oxide (FE(NO)) has been found reduced 4 to 6 weeks after an educational intervention in farmers with occupational asthma. OBJECTIVE To reveal whether long-term changes in FE(NO) would still be detectable a year after the intervention. METHODS We evaluated airway inflammation and obstruction at baseline and after 1 year in animal farmers with occupational asthma (n = 43, 16 women, mean [SD] age, 46.5 [8.9] years) who participated in a 1-day educational program, and in a control group of farmers without intervention (n = 15, 3 women, mean age, 44.1 [10.7] years). FE(NO), spirometry results, and questionnaire data were compared between measurements and between the intervention and control group. RESULTS In the intervention group, geometric mean (SEM) FE(NO) decreased from 31.5 (1.1) to 25.0 (1.1) parts per billion (ppb) (P = .001), whereas in the control group there was a slight but not statistically significant increase from 27.2 (1.2) to 30.7 (1.2) ppb. Spirometric values remained unchanged in both groups. CONCLUSIONS We found that FE(NO) was still decreased 1 year after an educational intervention in farmers with occupational asthma. It would thus seem that FE(NO), a noninvasive marker of airway inflammation that can be easily assessed in occupational field work, may be suitable for the evaluation of both short-term and long-term effects of preventive measures in occupational asthma.