TY - JOUR
T1 - Migraine and air pollution
T2 - A systematic review
AU - Portt, Andrea E.
AU - Orchard, Christa
AU - Chen, Hong
AU - Ge, Erjia
AU - Lay, Christine
AU - Smith, Peter M.
N1 - Funding Information:
Andrea E. Portt is financially supported by the University of Toronto Open Fellowship. Christa Orchard is financially supported by the University of Toronto Open Fellowship, the University of Toronto Data Science Institute Doctoral Fellowship, and the Ontario Graduate Scholarship.
Publisher Copyright:
© 2023 The Authors. Headache: The Journal of Head and Face Pain published by Wiley Periodicals LLC on behalf of American Headache Society.
PY - 2023/10
Y1 - 2023/10
N2 - Objective: To systematically synthesize evidence from a broad range of studies on the association between air pollution and migraine. Background: Air pollution is a ubiquitous exposure that may trigger migraine attacks. There has been no systematic review of this possible association. Methods: We searched for empirical studies assessing outdoor air pollution and any quantified migraine outcomes. We included short- and long-term studies with quantified air pollution exposures. We excluded studies of indoor air pollution, perfume, or tobacco smoke. We assessed the risk of bias with the World Health Organization's bias assessment instrument for air quality guidelines. Results: The final review included 12 studies with over 4,000,000 participants. Designs included case-crossover, case–control, time series, and non-randomized pre–post intervention. Outcomes included migraine-related diagnoses, diary records, medical visits, and prescriptions. Rather than pooling the wide variety of exposures and outcomes into a meta-analysis, we tabulated the results. Point estimates above 1.00 reflected associations of increased risk. In single-pollutant models, the percent of point estimates above 1.00 were carbon monoxide 5/5 (100%), nitrogen dioxide 10/13 (78%), ozone 7/8 (88%), PM2.5 13/15 (87%), PM10 2/2 (100%), black carbon 0/1 (0%), methane 4/6 (75%), sulfur dioxide 3/5 (60%), industrial toxic waste 1/1 (100%), and proximity to oil and gas wells 6/13 (46%). In two-pollutant models, 16/17 (94%) of associations with nitrogen dioxide were above 1.00; however, more than 75% of the confidence intervals included the null value. Most studies had low to moderate risks of bias. Where differences were observed, stronger quality articles generally reported weaker associations. Conclusions: Balancing the generally strong methodologies with the small number of studies, point estimates were mainly above 1.00 for associations of carbon monoxide, nitrogen dioxide, ozone, and particulate matter with migraine. These results were most consistent for nitrogen dioxide.
AB - Objective: To systematically synthesize evidence from a broad range of studies on the association between air pollution and migraine. Background: Air pollution is a ubiquitous exposure that may trigger migraine attacks. There has been no systematic review of this possible association. Methods: We searched for empirical studies assessing outdoor air pollution and any quantified migraine outcomes. We included short- and long-term studies with quantified air pollution exposures. We excluded studies of indoor air pollution, perfume, or tobacco smoke. We assessed the risk of bias with the World Health Organization's bias assessment instrument for air quality guidelines. Results: The final review included 12 studies with over 4,000,000 participants. Designs included case-crossover, case–control, time series, and non-randomized pre–post intervention. Outcomes included migraine-related diagnoses, diary records, medical visits, and prescriptions. Rather than pooling the wide variety of exposures and outcomes into a meta-analysis, we tabulated the results. Point estimates above 1.00 reflected associations of increased risk. In single-pollutant models, the percent of point estimates above 1.00 were carbon monoxide 5/5 (100%), nitrogen dioxide 10/13 (78%), ozone 7/8 (88%), PM2.5 13/15 (87%), PM10 2/2 (100%), black carbon 0/1 (0%), methane 4/6 (75%), sulfur dioxide 3/5 (60%), industrial toxic waste 1/1 (100%), and proximity to oil and gas wells 6/13 (46%). In two-pollutant models, 16/17 (94%) of associations with nitrogen dioxide were above 1.00; however, more than 75% of the confidence intervals included the null value. Most studies had low to moderate risks of bias. Where differences were observed, stronger quality articles generally reported weaker associations. Conclusions: Balancing the generally strong methodologies with the small number of studies, point estimates were mainly above 1.00 for associations of carbon monoxide, nitrogen dioxide, ozone, and particulate matter with migraine. These results were most consistent for nitrogen dioxide.
KW - ambient air pollution
KW - emergency department visits
KW - environment
KW - headache
KW - headache diary
KW - migraine
UR - http://www.scopus.com/inward/record.url?scp=85173456255&partnerID=8YFLogxK
U2 - 10.1111/head.14632
DO - 10.1111/head.14632
M3 - Review Article
C2 - 37795754
AN - SCOPUS:85173456255
SN - 0017-8748
VL - 63
SP - 1203
EP - 1219
JO - Headache
JF - Headache
IS - 9
ER -