Annual Review of Public Health - Volume 30, 2009

In this article, we present a discussion of two general ways in which the traditional randomized trial can be modified or adapted in response to the data being collected. We use the term adaptive design to refer to a trial in which characteristics of the study itself, such as the proportion assigned to active intervention versus control, change during the trial in response to data being collected. The term adaptive sequence of trials refers to a decision-making process that fundamentally informs the conceptualization and conduct of each new trial with the results of previous trials. Our discussion below investigates the utility of these two types of adaptations for public health evaluations. Examples are provided to illustrate how adaptation can be used in practice. From these case studies, we discuss whether such evaluations can or should be analyzed as if they were formal randomized trials, and we discuss practical as well as ethical issues arising in the conduct of these new-generation trials.

The United States ranks in the lower tiers of OECD countries in life expectancy, and recent studies indicate that socioeconomic inequalities in health have been widening in the past decades. Over this period, many rigorous longitudinal studies have identified important social, behavioral, and environmental conditions that might reduce health disparities if we could design effective interventions and make specific policy changes to modify them. Often, however, neither our policy changes nor our interventions are as effective as we hoped they would be on the basis of findings from observational studies. Reviewed here are issues related to causal inference and potential explanations for the discrepancy between observational and experimental studies. We conclude that more attention needs to be devoted to (a) identifying the correct etiologic period within a life-course perspective and (b) understanding the dynamic interplay between interventions and the social, economic, and environmental contexts in which interventions are delivered.

The Behavioral Risk Factor Surveillance System (BRFSS) is a large state-based telephone survey. BRFSS is designed to monitor the leading risk factors for morbidity and mortality in the United States at the local, state, and national levels. The BRFSS has proven to be a powerful tool for building heath-promotion activities. However, the use of telephone-based, random-digit-dial (RDD) methods in public health surveys and surveillance is at a crossroads. Rapid changes in telecommunication, declines in participation rates, increases in the required level of effort and associated costs are becoming key challenges for BRFSS. To maintain the highest data quality and service to the local and state health departments, BRFSS has adopted an ongoing effort to improve coverage and response to the survey. This article provides an overview of the issues faced by BRFSS and the strategies in place to address them.

Marked international differences in rates of asthma and allergies and the importance of family history highlight the primacy of interactions between genetic variation and the environment in asthma etiology. Environmental tobacco smoke (or secondhand smoke), ambient air pollutants, and endotoxin and/or other pathogen-associated molecular patterns are the ambient exposures studied most frequently for interactions with genetic polymorphisms in asthma. To date, results from the literature remain inconclusive. Most published studies are underpowered to study interactions between genetic polymorphisms and ambient exposures, each with weak effects. Strategies to increase power include cooperation across studies to increase sample sizes and improve measures of both exposure and asthma phenotypes. Genome-wide association studies hold promise for identifying unexpected gene environment interactions, but given the statistical power issues, candidate gene association studies will remain important. New tools are enabling the study of epigenetic mechanisms for environmental interactions.

A growing literature investigates associations between neighborhood social environments and coronary heart disease (CHD). After reviewing the literature, we present a theoretical model of the mechanisms through which geographic life environments may influence CHD, focusing particularly on the social-interactional environment. We suggest that, in addition to the common notions of social cohesion or fragmentation and social disorder, eco-epidemiologists should consider neighborhood identities and stigmatization processes. We posit that neighborhood social interactions affect the wide set of affective, cognitive, and relational experiences individuals have in their neighborhoods, which in turn influence the psycho-cognitive antecedents of behavior and in the end shape health behavior. Finally, we discuss key methodological challenges relevant to the advent of a new generation of neighborhood studies, including the operational definition of neighborhoods, nonresidential environments, ecometric measurement, model specification strategies, mediational models, selection processes and notions of empirical/structural confounding, and the relevance of observational versus interventional studies.

Even at high concentrations, arsenic-contaminated water is translucent, tasteless, and odorless. Yet almost every day, studies report a continually increasing plethora of toxic effects that have manifested in exposed populations throughout the world. In this article we focus on recent findings, in particular those associated with major contributions since 2006. Early life exposure, both in utero and in childhood, has been receiving increased attention, and remarkable increases in consequent mortality in young adults have been reported. New studies address the dose-response relationship between drinking-water arsenic concentrations and skin lesions, and new findings have emerged concerning arsenic and cardiovascular disease. We also review the increasing epidemiological evidence that the first step of methylation of inorganic arsenic to monomethylated arsenic (MMA) is actually an activation step rather than the first step in detoxification, as once thought. Hexavalent chromium differs from arsenic in that it discolors water, turning the water yellow at high concentrations. A controversial issue is whether chromium causes cancer when ingested. A recent publication supports the original findings in China of increased cancer mortality in a population where well water turned yellow with chromium.

Armed combat (also termed war or armed conflict) has profound direct and indirect impacts on the long-term physical and mental health of both military personnel and noncombatant civilians. Although most research has focused on immediate and short-term health consequences of war, an increasing number of studies have focused on the long-term health consequences for both veterans of military service and noncombatant civilians. However, these long-term studies focus almost entirely on posttraumatic stress disorder and other mental health problems; relatively few long-term studies have focused on physical injuries due to war and the impact of those injuries on relationships, work, and other aspects of life. This article reviews illustrative examples of the existing literature on these long-term health consequences of war, focusing not only on military veterans of several different armed conflicts but also on noncombatant civilian populations, including spouses and children of military veterans as well as refugees and internally displaced persons. Public health professionals can help address these problems.

Although mankind stands to obtain great benefit from nanotechnology, it is important to consider the potential health impacts of nanomaterials (NMs). This consideration has launched the field of nanotoxicology, which is charged with assessing toxicological potential as well as promoting safe design and use of NMs. Although no human ailments have been ascribed to NMs thus far, early experimental studies indicate that NMs could initiate adverse biological responses that can lead to toxicological outcomes. One of the principal mechanisms is the generation of reactive oxygen species and oxidant injury. Because oxidant injury is also a major mechanism by which ambient ultrafine particles can induce adverse health effects, it is useful to consider the lessons learned from studying ambient particles. This review discusses the toxicological potential of NMs by comparing the possible injury mechanisms and adverse health effects of engineered and ambient ultrafine particles.

Legislators and their scientific beneficiaries express growing concerns that the fruits of their investment in health research are not reaching the public, policy makers, and practitioners with evidence-based practices. Practitioners and the public lament the lack of relevance and fit of evidence that reaches them and barriers to their implementation of it. Much has been written about this gap in medicine, much less in public health. We review the concepts that have guided or misguided public health in their attempts to bridge science and practice through dissemination and implementation. Beginning with diffusion theory, which inspired much of public health's work on dissemination, we compare diffusion, dissemination, and implementation with related notions that have served other fields in bridging science and practice. Finally, we suggest ways to blend diffusion with other theory and evidence in guiding a more decentralized approach to dissemination and implementation in public health, including changes in the ways we produce the science itself.

Despite the many accomplishments of public health, a greater attention to evidence-based approaches is warranted. This article reviews the concepts of evidence-based public health (EBPH), on which formal discourse originated about a decade ago. Key components of EBPH include making decisions on the basis of the best available scientific evidence, using data and information systems systematically, applying program-planning frameworks, engaging the community in decision making, conducting sound evaluation, and disseminating what is learned. Three types of evidence have been presented on the causes of diseases and the magnitude of risk factors, the relative impact of specific interventions, and how and under which contextual conditions interventions were implemented. Analytic tools (e.g., systematic reviews, economic evaluation) can be useful in accelerating the uptake of EBPH. Challenges and opportunities (e.g., political issues, training needs) for disseminating EBPH are reviewed. The concepts of EBPH outlined in this article hold promise to better bridge evidence and practice.

In 2003, the Institute of Medicine (IOM) recommended voluntary certification of graduates achieving the Master of Public Health degree. The Association of Schools of Public Health (ASPH), the American Public Health Association, the Association of State and Territorial Health Officials, the National Association of County and City Health Officials, and the Association for Prevention Teaching and Research joined together to establish the National Board of Public Health Examiners (5). This new body will certify graduates of accredited schools and programs of public health who successfully pass their examination. If this certification becomes common, the debate will move to other questions such as (a) can those who lack a degree from a school of public health be certified through the same examination, or a similar one; (b) how will this general certificate relate to specialized areas of public health practice which are also learned elsewhere; and (c) how will we assess the public health competence of public health workers who do not have a professional education?

Reducing food marketing to children has been proposed as one means for addressing the global crisis of childhood obesity, but significant social, legal, financial, and public perception barriers stand in the way. The scientific literature documents that food marketing to children is (a) massive; (b) expanding in number of venues (product placements, video games, the Internet, cell phones, etc.); (c) composed almost entirely of messages for nutrient-poor, calorie-dense foods; (d) having harmful effects; and (e) increasingly global and hence difficult to regulate by individual countries. The food industry, governmental bodies, and advocacy groups have proposed a variety of plans for altering the marketing landscape. This article reviews existing knowledge of the impact of marketing and addresses the value of various legal, legislative, regulatory, and industry-based approaches to change.

*This PDF was amended on Aug. 5, 2009: See explanation at http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.pu.30.090805.200009

With reference to the Communication-Persuasion model, we describe various research issues and challenges when considering the health of Latinos, and implications for designing and evaluating health communication and behavior change efforts in this population. Latinos, collectively the nation's largest minority group, vary substantially in terms of socioeconomic and legal status, their country of origin and the extent of ongoing contact with that country, their region of residence within the United States, their generation status and levels of acculturation, and psychosocial factors. Health communication efforts with Latinos need to focus on family, cultural traditions, and collectivism while attending to acculturation, language, generation and national origin. The most extensive intervention topic in Latino health promotion has been the application of the lay health advisor model. This and other fundamental communication approaches, as well as audience and population characteristics, need to be considered within the context of dynamic and complex societal changes.

Controversy persists regarding the utility of school-based interventions for obesity prevention and control and for related health promotion. This article reviews the pertinent evidence, based partly on a recent systematic review and meta-analysis by the author and colleagues. Of 64 relevant papers, 21 papers representing 19 distinct studies met quality criteria; half of these were published since 2000. Despite marked variation in measures, methods, and populations that handicap interpretation of this literature, evidence clearly demonstrated that school-based interventions had significant effects on weight. Thus available research evidence does present a case for school-based interventions. Despite the fact that such evidence is limited to date, the urgency of the obesity and diabetes epidemics cries out for action. Intervention is warranted on the basis of both extant evidence and common sense, with methodologically robust evaluation concomitantly to test our assumptions and verify our intuition.

The Internet increasingly serves as a platform for the delivery of public health interventions. The efficacy of Internet interventions has been demonstrated across a wide range of conditions. Much more work remains, however, to enhance the potential for broad population dissemination of Internet interventions. In this article, we examine the effectiveness of Internet interventions, with particular attention to their dissemination potential. We discuss several considerations (characterizing reach rates, minimizing attrition, promoting Web site utilization, use of tailored messaging and social networking) that may improve the implementation of Internet interventions and their associated outcomes. We review factors that may influence the adoption of Internet interventions in a range of potential dissemination settings. Finally, we present several recommendations for future research that highlight the potential importance of better understanding intervention reach, developing consensus regarding Web site usage metrics, and more broadly integrating Web 2.0 functionality.

Cost-sharing is a health care cost-containment technique in which health care services are partially paid for by patients out of pocket. Cost-sharing can reduce non-cost-effective care, but it can also undermine the financial protection and access values of health insurance. We review the empirical evidence published since the mid-1980s about cost-sharing's effect on utilization, expenditures, health, and adverse consequences, including how the effects vary by form of care, by health status, and by sociodemographic characteristics. Some cost-sharing, such as emergency department copayments, reduces utilization without any harmful effects, whereas other cost-sharing reduces valuable care such as maintenance drug use among the chronically ill. Cost-sharing should be used judiciously, with attention taken not to reduce highly cost-effective care.

The veterans health care system administered by the U.S. Department of Veterans Affairs (VA) was established after World War I to provide health care for veterans who suffered from conditions related to their military service. It has grown to be the nation's largest integrated health care system.

As the system grew, a number of factors contributed to its becoming increasingly dysfunctional. By the mid-1990s, VA health care was widely criticized for providing fragmented and disjointed care of unpredictable and irregular quality, which was expensive, difficult to access, and insensitive to individual needs.

Between 1995 and 1999, the VA health care system was reengineered, focusing especially on management accountability, care coordination, quality improvement, resource allocation, and information management. Numerous systemic changes were implemented, producing dramatically improved quality, service, and operational efficiency. VA health care is now considered among the best in America, and the VA transformation is viewed as a model for health care reform.

Setting priorities on the basis of factors such as health impact and economic value is the key first step to ensure that the most important services receive the most attention. Few prioritization efforts have been published that produce either rankings or information that can guide decision making. We propose a framework to help decision makers and clinicians balance short-term demands against long-term objectives. This framework provides guidance for decisions about scope, prioritization criteria, evidence review methods, evaluation of criteria fit, and presentation of results. The framework is the result of our experience setting priorities among clinical preventive services. It has not been tested in prioritizing community interventions and other health care services but should provide a useful starting point for designing priority-setting efforts in those areas.

This article asks whether financial incentives can improve the quality of health care. A conceptual framework drawn from microeconomics, agency theory, behavioral economics, and cognitive psychology motivates a set of propositions about incentive effects on clinical quality. These propositions are evaluated through a synthesis of extant peer-reviewed empirical evidence. Comprehensive financial incentives—balancing rewards and penalties; blending structure, process, and outcome measures; emphasizing continuous, absolute performance standards; tailoring the size of incremental rewards to increasing marginal costs of quality improvement; and assuring certainty, frequency, and sustainability of incentive payoffs—offer the prospect of significantly enhancing quality beyond the modest impacts of prevailing pay-for-performance (P4P) programs. Such organizational innovations as the primary care medical home and accountable health care organizations are expected to catalyze more powerful quality incentive models: risk- and quality-adjusted capitation, episode of care payments, and enhanced fee-for-service payments for quality dimensions (e.g., prevention) most amenable to piece-rate delivery.