Send Orders of Reprints at bspsaif@emirates.net.ae The Open Epidemiology Journal, 2013, 6, 1-8 1 1874-2971/13 2013 Bentham Open Open Access Workshop Report: Evaluation of Epidemiological Data Consistency for Application in Regulatory Risk Assessment § Ronald H. White *,1 , Mary A. Fox 2 , Glinda S. Cooper 3 , Thomas F. Bateson 3 , Thomas A. Burke 2 and Jonathan M. Samet 4 1 R.H. White Consultants, Silver Spring, MD, USA 2 Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA 3 National Center for Environmental Assessment, U.S. Environmental Protection Agency, Washington DC, USA 4 Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA Abstract: Epidemiological study results have a key role in the assessment of health risks associated with exposures to chemicals and pollutants, and often serve as the basis for the development of regulatory limits for environmental and occupational health. A key uncertainty in the application of epidemiological study results in risk assessments stems from variability in defining and operationalizing the concept of consistency of findings across studies, with assessments of consistency often a controversial component of risk assessments. Although assessment of consistency of findings across a diverse collection of epidemiological studies is central to evaluating that body of evidence for supporting causal inferences, the variability in definition and formal evaluation methods strongly suggest the need for constructive approaches to consistently and transparently evaluate data consistency. In response to the need to improve approaches to assessing consistency in epidemiological study results, the Johns Hopkins Risk Sciences and Public Policy Institute organized a workshop held in Baltimore, Maryland in September 2010 to identify and discuss key methodological issues, and to develop recommendations for qualitative and quantitative approaches to addressing those issues. A multi-disciplinary approach was utilized for the workshop, involving invited experts from a variety of fields, and the invited participants were drawn from academia, industry, government, and the public interest sectors. This report provides a summary of selected epidemiology methodological issues discussed by the workshop participants and provides the workshop’s key findings and recommendations for future approaches to addressing this issue. Keywords: Consistency, epidemiology, heterogeneity, regulation, risk assessment, workshop report. INTRODUCTION Epidemiological studies play a key role in the assessment of risks associated with exposures to chemicals and pollutants and for development of regulatory standards covering environmental and occupational settings. The strengths and weaknesses of epidemiological methodology, as well as the overall value of the use of epidemiological evidence to support regulatory standards, have been widely discussed in the scientific and public health policy literature (e.g., [1-8]). Issues related to the presentation of epidemiological results that inform risk assessments, the need to apply modern biostatistical techniques to *Address correspondence to this author at the R.H. White Consultants, LLC, 12900 Tourmaline Terrace, Silver Spring, MD, USA; Tel: (240) 381-4075; Fax: (301) 384-8876; E-mail: ronaldhwhite@comcast.net § The views expressed in this article are those of the authors and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency, the National Institute of Environmental Health Sciences, the National Institute of Occupational Safety and Health, or Health Canada. epidemiological data, and methodological challenges in the use of epidemiological data in quantitative risk assessment have also been noted [9-12]. When evaluating epidemiological findings in support of causal inference, a key uncertainty often stems from apparent inconsistency across studies. Evaluations of consistency are often controversial, and contradictory determinations may result from varying stakeholder perspectives. The evaluation of consistency in epidemiological results has been discussed for more than 50 years (e.g., [13-15]), expanding and become more nuanced as the field of epidemiology (and specifically environmental epidemiology) has matured. For example, gender-based differences in susceptibility to a potential endocrine-disrupting chemical can explain differences in observed effects among studies that include varying proportions of males and females – i.e., there may be biological reasons not to expect to see the same effect. Similarly, differences in exposure metrics and the range of exposures could lead to differences in observed estimates among studies. The evaluation of consistency of findings across a diverse collection of epidemiological studies is