Medication use in populations exposed to the 2010 Eyjafjallajökull eruption: an interrupted time series analysis

• Published in: BMJ Open
• Main Authors: Guðmundsdóttir, Rebekka Björg, Jónsson, Brynjólfur Gauti Guðrúnar, Valdimarsdottir, Unnur, Carlsen, Hanne Krage, Hlodversdottir, Heidrun, Song, Huan, Thordardottir, Edda Bjork, Pétursdóttir, Guðrún, Briem, Haraldur, Gislason, Thorarinn, Gudnason, Thorolfur, Thorsteinsson, Thröstur, Zoega, Helga, Hauksdóttir, Arna
• Other Authors: Icelandic Research Fund, Nordic Centre of Excellence for Resilience and Societal Security
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMJ 2022
• Subjects: General Medicine; Eyjafjallajökull; Iceland
• Online Access: http://dx.doi.org/10.1136/bmjopen-2021-059375; https://syndication.highwire.org/content/doi/10.1136/bmjopen-2021-059375

Objectives To assess the trends in medication use indicative of physical and psychological morbidity following the 2010 volcanic eruption in Eyjafjallajökull immediately after and during a 3-year period following the eruption. Design Population-based register study. Setting Eyjafjallajökull eruption in Iceland, 2007–2013. Participants All residents in Iceland who received at least one medication dispensing were identified. Residents of exposed areas were classified into exposure groups (individual-level data) and residents in other parts of Iceland were included as a non-exposed group (aggregated data). Intervention/exposure Eyjafjallajökull erupted on 14 April 2010 and continued for 39 days, producing heavy ash fall in South Iceland. Main outcome measures Using interrupted time series analysis, we examined annual and quarterly changes in medicine use, measured as number of dispensed defined daily dose (DDD) per 1000 individuals. We calculated the level shift (immediate change) and change in slope from pre-eruption to post-eruption (long-term change) in medication dispensing. Results Among exposed residents, there was a 6% decrease (95% CI -7% to -4%) in the annual number of dispensed DDDs 1-year post-eruption in the overall medication class, including analgesics (−5%, 95% CI -6% to -3%), hypnotics and sedatives (−9%, 95% CI -11% to -7%) and respiratory medications (−7%, 95% CI -9% to -5%; −8%, 95% CI -11% to -4%). Simultaneously, there was a 9% decrease (95% CI -14% to -4%) in the overall medication class among non-exposed residents. Moreover, among exposed residents, we observed change in slope of −4% (95% CI -7% to -1%) in the overall medication class, including for analgesics (−6%, 95% CI -8% to -3%) and other respiratory drugs (−10%, 95% CI -16% to -4%). Conclusion Our findings indicate that the eruption did not lead to increases in medication dispensing among residents of exposed areas, rather decreases for some medicine classes. The results should be interpreted with caution since the content of each ...