The Public’s Love/Hate Relationship with Epidemiology: The Burden of Being Relevant David A. Savitz Departments of Epidemiology and Obstetrics & Gynecology Brown University Overview of Presentation How epidemiology’s home in the real world affects the discipline Relationship of epidemiology to public health Case study: Health effects of contaminated drinking water at Camp Lejeune, North Carolina Epidemiology is Intertwined in the Real World World is our research setting Public funds our research Research methods, findings, and implications are accessible and of interest to the educated public Findings help to guide societal and individual decisions Benefits of Public Interest to the Field of Epidemiology Assistance in implementing studies Financial support for research Receptive audience for our guidance on policy and behavior Media attention Respect and appreciation for us and our work the-new-yorker-epi.jpg How Epidemiology Disappoints the Public Fail to bring closure to controversies Instability of findings and recommendations Disagreement among the experts Raises fears about enjoyable or beneficial exposures How Epidemiology Disappoints the Public, continued Loss of confidence in objectivity Paid advocacy Ideologically tainted research Manipulation of the public to generate research funding Failure to support what they “know” to be true How the Public’s Interest Affects Practice of Epidemiology Incentive to manipulate science to fit personal ideology Be wary of those who generate data that consistently support desired policy or politics Increased attention to financial conflicts of interest, but deep personal convictions may be more insidious and powerful How the Public’s Interest Affects Epidemiology, continued Opportunity to pander for fame (media attention) or fortune (research funding) Incentive to overstate or understate certainty of evidence Overstate to justify action Understate to perpetuate controversy and research funding that results Relationship of Epidemiology to Public Health Epidemiology is a scientific discipline Study of the distribution and determinants of disease in human populations Choice of questions and applications of evidence guided by societal concerns Objective Contributes knowledge to public health, biomedical science, clinical medicine, public policy Relationship of Epidemiology and Public Health Public health is “the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals” (CEA Winslow, 1920) Characteristics of Public Health Focused on providing benefit to the public’s health using diverse approaches Draws on multiple lines of scientific evidence – epidemiology, human biology, economics, political science, psychology, etc. Integrates non-scientific considerations – ethics, social justice, individual autonomy Judgment in the face of uncertainty – balanced weighing of alternative courses of action to optimize public health benefit Dangers when Public Health is Overly Reliant on Epidemiology Implies that the absence of definitive epidemiologic data precludes action Ammunition for public health opponents Undervalues other lines of evidence, non-scientific considerations Incentive to overstate persuasiveness of epidemiologic evidence Dangers When Public Health is Overly Reliant on Epidemiology, continued Implies presence of epidemiologic data demands action Danger that epidemiologic evidence may run counter to beneficial public health action Incentive to dismiss epidemiologic research based on its implications rather than based on the quality of the research Dangers When Public Health is Overly Reliant on Epidemiology, continued Danger of seeking epidemiologic evidence to support, not assess, policy Research findings are unpredictable by definition – evidence may not cooperate Incentive to bend the research findings Some, not all, policy decisions tipped by further epidemiologic evidence; but if the policy choice is clear, why do epidemiology at all? Revised Description of the Role of Epidemiology in Public Health Replace “Epidemiology is the basic science of public health” With “Epidemiology is an important source of scientific evidence that often helps to inform public health actions” Health Effects of Contaminated Water at Camp Lejeune Committee of the National Research Council appointed to address longstanding concerns Disclaimer – my views, not Committee consensus Illustration of controversial public health issue and the role of epidemiology in addressing it History of Water Contamination Episode at Camp Lejeune Discovery in mid-1980s of contaminated water supply for Camp Lejeune, US Marine base, origins around middle 1950s Primarily trichloroethylene (TCE) and perchloroethylene (PCE) from off-base dry cleaners through ground water leaching; also chemicals from on-site industrial activities Contaminated water served family housing, barracks, offices, schools, hospital, etc. History of Water Contamination Episode at Camp Lejeune, cont. Use of contaminated water ended 1984-1985 ATSDR assessment in late 1990s found risk to adults unlikely, but reproductive risks possible Studies of birth records found no overall effect on birthweight, but increased risk in some subgroups (Sonnenfeld et al., 1991) ATSDR studies of birth defects, childhood cancers in progress Charge to Committee Congress directed US Navy to assess evidence on whether adverse health outcomes are associated with past contamination of the water supply Review scientific evidence on health effects of TCE, PCE, and other contaminants of concern Evaluate completed & ongoing studies of former residents, assess value of new studies Identify scientific considerations to help Navy set priorities on future activities Multiple Interested Parties with Varying Expectations US Navy (Marines) Seeking closure to controversy, clear and definitive plan of action to satisfy Congress, former residents Former Camp Lejeune residents Seeking vindication for health problems that occurred after exposure, conclusion that contaminated water caused health problems, acknowledgment that US Navy was dishonest in handling situation Multiple Interested Parties with Varying Expectations, cont. ATSDR Past, ongoing, and future studies are informative and essential for addressing health concerns NRC and Committee members Insightful, dispassionate evaluation will provide clear path forward and satisfy all the interested parties Exposure to Contaminants in Water Supply Water supplies clearly were contaminated with TCE, PCE, and other volatile organic compounds for decades, ending in 1980s Exposure cannot be quantified due to lack of historical measurements or detailed records of water treatment methods Exposure to Contaminants in Water Supply, cont. ATSDR’s estimates of monthly concentrations use very complex, sophisticated models, and overstate accuracy Recommend use of simple models – equally valid results, quickly and inexpensively Review of Toxicology of TCE and PCE: Outcomes of Concern Cancer: lung, liver, kidney Renal toxicity Immune suppression Reversible and irreversible neurobehavioral effects Male infertility Congenital malformations Fetal growth restriction Review of Epidemiologic Evidence on TCE and PCE No outcomes with established causal effect “Limited/suggestive evidence” for: Cancer – breast, bladder, kidney, esophagus, lung Hepatic steatosis, acute tubular necrosis, acute glomerulonephritis Scleroderma Male and female infertility, miscarriage Reversible neurobehavioral effects Completed Camp Lejeune Studies: Methods Focus on in utero exposure to TCE and PCE Outcomes: birth weight, preterm birth Singleton births in 1968-85 to residents of base housing (based on available records) Exposure to contaminated water determined by housing records Covariates from birth certificates Completed Camp Lejeune Studies: Results from Sonnenfeld et al. (2001) Exposed women more often non-white, less educated, fewer in officers’ housing Mean birthweight lower among exposed: -26 g (90% CI = -43, -9) OR for preterm birth = 1.0 (0.9-1.1) OR for SGA = 1.2 (1.0-1.3) Stronger association among mothers >35, those with >2 fetal losses Completed Camp Lejeune Studies: Findings & Recommendations Error in exposure assignment discovered: ~25% of those assigned as “unexposed” were exposed to contaminated water Limitations in information on timing of exposure, pregnancy outcomes, covariates Proceed with reanalysis correcting for known misclassification promptly New water model not worth waiting for Camp Lejeune Studies: Ongoing Study Design and Methods ATSDR concerned with childhood cancer (leukemia, non-Hodgkins lymphoma) and birth defects (spina bifida, anencephaly, cleft lip, cleft palate) Case identification through telephone survey of 12,598 mothers who gave birth 1968-1995 (survey conducted 1999-2002) Identified 29 childhood cancers, 35 neural tube defects, 42 oral cleft cases Camp Lejeune Studies: Ongoing Study Progress and Plans Of 35 neural tube defects, 15 confirmed, 13 ruled out Of 42 oral clefts, 24 confirmed, 11 ruled out Of 29 childhood leukemia/lymphoma cases, 13 confirmed, 8 ruled out Minimum detectable ORs of 2.5-4.5 Awaiting completion of water modeling to conduct case-control study among base residents Camp Lejeune Studies: Ongoing Findings and Recommendations Exposure assessment is and will remain major limitation, don’t wait for refinements Inadequate statistical power for very rare outcomes under investigation Recommend rapid completion of studies given effort already expended Simplify, accelerate, and truncate research effort to bring it to a prompt close Camp Lejeune Studies: Future Studies Health survey of current and former base residents Mandated by Congress Call for mailed questionnaire Mortality study Compare Camp Lejeune military and civilian residents to Camp Pendleton residents Cancer incidence study Match records to state cancer registries Camp Lejeune Studies: Future Committee Concerns Exposure limitations are insurmountable Incomplete roster of former residents Mostly short-term exposures Potentially biased participation and response Mortality study likely to be feasible, other studies of uncertain feasibility Relatively young population, limited numbers of deaths and serious diseases Camp Lejeune Studies: Future Committee Recommendations More complete evaluation could describe health experience more fully Limited exposure data; size, age, and mobility of population; record availability, “the committee concludes that it would be extremely difficult to conduct direct epidemiologic studies of sufficient quality and scope to make a substantial contribution to resolving the health concerns of former Camp Lejeune residents” Committee’s Recommendations on Further Epidemiologic Research Only undertake new studies if feasibility and promise of advancing understanding of health effects for this population is established Response to health concerns resulting from exposure to contaminated water should not be delayed awaiting results of epidemiologic studies given their limited promise for providing definitive information on health effects Reactions to Report US Navy – little comment or response Former Camp Lejeune residents Belief that we stated exposures did not cause health harm and failed to confirm that exposures caused their health problems We failed to recognize that toxic chemicals other than TCE and PCE were present We were biased towards exonerating the US Navy Engagement of Congress for vindication Reactions to Report, cont. ATSDR Elaborate water modeling is needed and helpful in quantifying exposure Studies have sufficient power and will be able to determine whether Camp Lejeune water contamination caused adverse health effects Other review groups have supported their plans for more research NRC Committee’s Response Disappointment over misinterpretation of our lack of enthusiasm for more epidemiologic research Recognition of the power of epidemiologic research as tool for procrastination Concern with researchers using controversy to advocate for research Need to avoid overpromising what scientific evaluation can provide General Lessons for Epidemiologists Engaging in the Real World Important to clarify what epidemiology can and cannot offer at the outset – it’s research, not public health service, advocacy, or justice Focus on adequacy of methods and clarity regarding the strength of inferences that will result: only proceed if attainable increment in knowledge is beneficial Results are not predictable and should not be presumed to support a course of action General Lessons for Epidemiologists Engaging in the World, cont. Be willing to discourage epidemiology when it’s not part of the solution Guard against advocacy-based epidemiology – misleads advocates, compromises epidemiologists Vital role for epidemiologists in public health Generate and interpret evidence dispassionately Clearly explain research methods and findings Contribute to formulation of policy Postscript: HR1627, April 2012 Bill passed with bipartisan support, up to 1,000,000 exposed to tainted groundwater Provides health benefits for Marines and their families who were exposed to contaminated water at a North Carolina Marine Base: diseases with “limited/suggestive evidence” from NRC report “I think all Americans feel we have a moral, sacred duty toward our men and women in uniform…“And, sadly, this act alone will not bring back those we’ve lost, including Jane Ensminger, but it will honor thei rmemory by making a real difference for those who are still suffering” General Lessons for Epidemiologists Engaging in the World, cont. Be willing to discourage epidemiology when it’s not part of the solution Guard against advocacy-based epidemiology – misleads advocates, compromises epidemiologists Vital role for epidemiologists in public health Generate and interpret evidence dispassionately Clearly explain research methods and findings Contribute to formulation of policy Postscript: HR1627, April 2012 Bill passed with bipartisan support, up to 1,000,000 exposed to tainted groundwater Provides health benefits for Marines and their families who were exposed to contaminated water at a North Carolina Marine Base: diseases with “limited/suggestive evidence” from NRC report “I think all Americans feel we have a moral, sacred duty toward our men and women in uniform…“And, sadly, this act alone will not bring back those we’ve lost, including Jane Ensminger, but it will honor thei rmemory by making a real difference for those who are still suffering”