Bias in the case - crossover design: implications for studies of air pollution

2000 ◽  
Vol 11 (6) ◽  
pp. 689-704 ◽  
Author(s):  
Thomas Lumley ◽  
Drew Levy
2005 ◽  
Vol 24 (2) ◽  
pp. 285-300 ◽  
Author(s):  
Holly Janes ◽  
Lianne Sheppard ◽  
Thomas Lumley

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1152
Author(s):  
Shuo-Ping Hsieh ◽  
Chia-Jung Hsieh ◽  
Chun-Chieh Tseng ◽  
Lih-Ming Yiin

Allergic conjunctivitis (AC) and rhinitis (AR) are common allergic diseases that may be environmentally related. We used a systematic sampling cohort database, which was applied in an AC study previously, to examine the association of AR with air pollution and weather changes. A case-crossover design coupled with conditional logistic analysis was implemented in the analysis; we identified 140,365 eligible AR subjects, and matched their diagnoses with environmental monitoring data. Unlike AC, the descriptive statistics indicated that AR occurred the most in adults under 50 years old by age (44.7%), and in winter by season (28.7%) (p < 0.001); similar to AC, AR occurred more in women than to men. Nitrogen dioxide (NO2) was found to be positively associated with AR (p < 0.001), whereas relative humidity and temperature were negatively related (p < 0.001). We found that the risk of AR increased with descending NO2 levels relative to AC (OR = 0.984, p = 0.003) after adjustment for covariates. It is suggested that AR could be triggered or exacerbated by lower levels of NO2 than is AC. We recommend that AR patients pay extra attention to air pollution and mitigate their allergic problem accordingly.


2020 ◽  
Vol 9 (11) ◽  
pp. 3445
Author(s):  
Łukasz Kuźma ◽  
Emil Julian Dąbrowski ◽  
Anna Kurasz ◽  
Hanna Bachórzewska-Gajewska ◽  
Sławomir Dobrzycki

The detrimental influence of air pollution on mortality has been established in a series of studies. The majority of them were conducted in large, highly polluted cities—there is a lack of studies from small, relatively clean regions. The aim was to analyze the short-term impact of particulate matters (PMs) on mortality in north-eastern Poland. Time-stratified case-crossover design was performed for mortality in years 2008–2017. Daily concentrations of PM2.5 (28.4 µg/m3, interquartile range (IQR) = 25.2) vs. (12.6 µg/m3, IQR = 9.0) and PM10 (29.0 µg/m3, IQR = 18.0) vs. (21.7 µg/m3, IQR = 14.5) were higher in Łomża than Suwałki (p < 0.001). Impact of PM2.5 on mortality was recorded in Łomża (odds ratio (OR) for IQR increase 1.061, 1.017–1.105, p = 0.06, lag 0) and Suwałki (OR for IQR increase 1.044, 1.001–1.089, p = 0.004, lag 0). PM10 had an impact on mortality in Łomża (OR for IQR increase 1.028, 1.000–1.058, p = 0.049, lag 1). Cardiovascular mortality was affected by increase of PM2.5 in Łomża (1.086, 1.020–1.156, p = 0.01) and Suwałki (1.085, 1.005–1.171, p = 0.04). PM2.5 had an influence on respiratory mortality in Łomża (1.163, 1.021–1.380, p = 0.03, lag 1). In the whole studied region, despite differences in the air quality, the influence of PMs on mortality was observed.


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