title: Methodological issues related to pooling results from panel studies of heart rate variability and its association with ambient air pollution.
abstract: Reviews of observational studies and subsequent meta-analyses are challenging to interpret because of potential methodological issues and biases inherent in studies. In reviewing panel studies of the association between heart rate variability and ambient air pollution we identified a number of methodological issues that make difficult interpreting and pooling findings from longitudinal studies, notably issues related to associations arising from different type of designs, differences in design characteristics, including study populations, measurements of heart rate variability (e.g., duration and condition of the electrocardiogram recordings), exposure assessment (e.g., types of monitoring), metrics of exposure used, and parameters estimated from regression models. We conclude that many panel studies of the association between heart rate variability and ambient air pollution may not be comparable to each other, and thus caution must be exercised to avoid misleading conclusions.
authors.affiliation: Department of Medicine, McGill University, Montreal, Quebec, Canada; Institut National de Sante Publique du Quebec (INSPQ), Montreal, Quebec, Canada. Electronic address: stephane.buteau@mail.mcgill.ca.
authors.forename: Stephane
authors.initials: S
authors.lastname: Buteau
authors.affiliation: Department of Medicine, McGill University, Montreal, Quebec, Canada; Division of Clinical Epidemiology, McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Goldberg
mesh_terms: D000397:Air Pollution; D006339:Heart Rate; D006801:Humans; D008962:Models, Theoretical
keywords: Ambient air pollution; Heart rate variability; Longitudinal cohort study (panel study); Meta-analysis