Daily diaries of respiratory symptoms and air pollution: Methodological issues and results

Journal Article · Tue Jan 01 00:00:00 EST 1991 · Environmental Health Perspectives; (United States)

DOI:https://doi.org/10.2307/3430866· OSTI ID:5074163

Schwartz, J ^[1]; Wypij, D; Dockery, D; Ware, J; Spengler, J; Ferris, B Jr ^[2]; Zeger, S ^[3]

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1. Environmental Protection Agency, Washington, DC (United States)
2. Harvard School of Public Health, Boston, MA (United States)
3. Johns Hopkins School of Hygiene and Public Health, Baltimore, MD (United States)

Daily diaries of respiratory symptoms are a powerful technique for detecting acute effects of air pollution exposure. While conceptually simple, these diary studies can be difficult to analyze. The daily symptom rates are highly correlated, even after adjustment for covariates, and this lack of independence must be considered in the analysis. Possible approaches include the use of incidence instead of prevalence rates and autoregressive models. Heterogeneity among subjects also induces dependencies in the data. These can be addressed by stratification and by two-stage models such as those developed by Korn and Whittemore. These approaches have been applied to two data sets: a cohort of school children participating in the Harvard Six Cities Study and a cohort of student nurses in Los Angeles. Both data sets provide evidence of autocorrelation and heterogeneity. Controlling for autocorrelation corrects the precision estimates, and because diary data are usually positively autocorrelated, this leads to larger variance estimates. Controlling for heterogeneity among subjects appears to increase the effect sizes for air pollution exposure. Preliminary results indicate associations between sulfur dioxide and cough incidence in children and between nitrogen dioxide and phlegm incidence in student nurses.

• OSTI ID: 5074163
• Journal Information: Environmental Health Perspectives; (United States), Vol. 90; ISSN 0091-6765
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
POLLUTANTS
BIOLOGICAL EFFECTS
RESPIRATORY SYSTEM DISEASES
RISK ASSESSMENT
AIR POLLUTION
CHILDREN
DISEASE INCIDENCE
LOS ANGELES
MATHEMATICAL MODELS
NITROGEN DIOXIDE
REGRESSION ANALYSIS
SULFUR DIOXIDE
AGE GROUPS
CALIFORNIA
CHALCOGENIDES
DEVELOPED COUNTRIES
DISEASES
FEDERAL REGION IX
MATHEMATICS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
POLLUTION
STATISTICS
SULFUR COMPOUNDS
SULFUR OXIDES
USA
560300* - Chemicals Metabolism & Toxicology