Analysis of the influence of pollen levels on emergency visits for exacerbations of bronchial asthma in southern Spain

BackgroundEpidemiological studies consistently highlight the adverse impact of pollen on asthma exacerbations. This study investigates the correlation between pollen levels and asthma-related Emergency Department visits across four Andalusian provinces, with a combined population of 3.8 million, from 2017 to 2019. Materials and methodsA bidirectional case-crossover design was applied up to 4 lag days to calculate odds ratios (OR) for admissions, adjusting for daily pollen levels and incorporating meteorological factors and personal information as covariates. ResultsSignificant associations (95% CI) were found between pollen exposure and asthma-related Emergency Department visits, varying by pollen type, region, and lag day. In Almeria, gramineae (1-day lag, OR 1.20); in Huelva, artemisia (1-day lag, OR 1.13), betula (3-day lag, OR 1.26), and olea (1- and 2-day lags, OR 1.20); in Jaen, gramineae (0- and 1-day lags, OR {approx} 9.97), olea (0-4 days, OR {approx} 1.20), and plantago (0-to 2-day lags, OR {approx} 1.20); and in Seville, alternaria (1-4 day lags, OR {approx} 9.96), carex (0-3 day lags, max OR 1.72 at 2 days), olea (0-4 days, OR {approx} 1.20) and urticaceae (same day, OR 1.02). ConclusionThis study provides a comprehensive understanding of pollens role in asthma exacerbations, with specific pollen types showing regional and temporal variation. Findings support further research on regional pollen thresholds and geolocation-based strategies to notify asthma patients. Summary boxWhat do we know about this topic? How does this study impact our current understanding and/or clinical management of this topic?