Referent selection in case-crossover analyses of acute health effects of air pollution

Levy, D; Lumley, T; Sheppard, L; Kaufman, J; Checkoway, H

HERO ID

17172

Reference Type

Journal Article

Year

2001

PMID

11246579

HERO ID 17172
In Press No
Year 2001
Title Referent selection in case-crossover analyses of acute health effects of air pollution
Authors Levy, D; Lumley, T; Sheppard, L; Kaufman, J; Checkoway, H
Journal Epidemiology
Volume 12
Issue 2
Page Numbers 186-192
Abstract The case-crossover design was proposed for the study of a transient effect of an intermittent exposure on the subsequent occurrence of a rare acute-onset disease. This design can be an alternative to Poisson time series regression for studying the health effects of fine particulate matter air pollution. Characteristics of time-series of particulate matter, including long-term time trends, seasonal trends, and short-term autocorrelations, require that referent selection in the case-crossover design be considered carefully and adapted to minimize bias. We performed simulations to evaluate the bias associated with various referent selection strategies for a proposed case-crossover study of associations between particulate matter and primary cardiac arrest. Some a priori reasonable strategies were associated with a relative bias as large as 10%, but for most strategies the relative bias was less than 2% with confidence interval coverage within 1% of the nominal level. We show that referent selection for case-crossover designs raises the same issues as selection of smoothing method for time series analyses. In addition, conditional logistic regression analysis is not strictly valid for some case-crossover designs, introducing further bias.
Doi 10.1097/00001648-200103000-00010
Pmid 11246579
Wosid WOS:000167139400010
Is Certified Translation No
Dupe Override No
Comments ECRIB.Epidemiology 12: 186-192.
Is Public Yes
Keyword study design; data analysis; case-crossover design; bias; pollution
Is Qa No