[Characteristics of asthma cases reported as a suspected occupational disease in Navarra. Period 2010-2015]

Although, occupational asthma (OA) causes great work disability, due to its diagnostic complexity, it is difficult to have it recognized by the official registration systems. To improve its detection, suspected systems have been developed. After years of experience in Navarre, we set out to characterize the suspected cases and compare them with those declared as an occupational disease (OD).

We identified the cases of OA reported as sentinel events in the Epidemiological Surveillance Program in Occupational Health in Navarra from January 2010 to December 2015 and the cases declared as OD (asthma). The population under study was the Navarra employed population (357,200 on average). In the cases with consent, the clinical and labor characteristics were compared with those of OD. Using the SPSS Statistics® 20v computer program, mean differences were calculated by the T test for independent samples and distribution percentage differences by Chi-square test, Fisher's exact test and nonparametric tests when application conditions were not satisfied. As an indicator of notification, the accumulated incidence per 100,000 workers was calculated for each year of program monitoring.

In the period, 79 sentinel events were reported (in 22 the investigation was concluded) and 50 cases of OD (24% relapses). We did not find statistically significant differences in age (41 vs. 40 years), nor gender (40.9% women vs. 44.7%), nor proportion that caused sick leave (45% and 36.8%), nor size, activity of the company or occupation of the worker. Where differences are found was in the meantime of exposure before the recognition/notification, significantly higher in the OD than in the sentinel (94.1 vs. 22.2 months), 72 months longer.

The cases detected by both systems are similar but, due to the diagnostic complexity, the recognition is delayed as OD, which demonstrates the usefulness of a more agile system for reporting suspicions of this work pathology.