Projected health impact of the Los Angeles City living wage ordinance

Developing an integrated microsimulation model for the impact of fiscal policies on child health in Europe: the example of childhood obesity in Italy

BACKGROUND

We developed an integrated model called Microsimulation for Income and Child Health (MICH) that provides a tool for analysing the prospective effects of fiscal policies on childhood health in European countries. The aim of this first MICH study is to evaluate the impact of alternative fiscal policies on childhood overweight and obesity in Italy.

METHODS

MICH model is composed of three integrated modules. Firstly, module 1 (M1) simulates the effects of fiscal policies on disposable household income using the tax-benefit microsimulation program EUROMOD fed with the Italian EU-SILC 2010 data. Secondly, module 2 (M2) exploits data provided by the Italian birth cohort called Nascita e Infanzia: gli Effetti dell'Ambiente (NINFEA), translated as Birth and Childhood: the Effects of the Environment study, and runs a series of concatenated regressions in order to estimate the prospective effects of income on child body mass index (BMI) at different ages. Finally, module 3 (M3) uses dynamic microsimulation techniques that combine the population structure and incomes obtained by M1, with regression model specifications and estimated effect sizes provided by M2, projecting BMI distributions according to the simulated policy scenarios.

RESULTS

Both universal benefits, such as universal basic income (BI), and targeted interventions, such as child benefit (CB) for poorer households, have a significant effect on childhood overweight, with a prevalence ratio (PR) in 10-year-old children-in comparison with the baseline fiscal system-of 0.88 (95%CI 0.82-0.93) and 0.89 (95%CI 0.83-0.94), respectively. The impact of the fiscal reforms was even larger for child obesity, reaching a PR of 0.67 (95%CI 0·50-0.83) for the simulated BI and 0.64 (95%CI 0.44-0.84) for CB at the same age. While both types of policies show similar effects, the estimated costs for a 1% prevalence reduction in overweight and obesity with respect to the baseline scenario is much lower with a more focalised benefit policy than with universal ones.

CONCLUSIONS

Our results show that fiscal policies can have a strong impact on childhood health conditions. Focalised interventions that increase family income, especially in the most vulnerable populations, can help to prevent child overweight and obesity. Robust microsimulation models to forecast the effects of fiscal policies on health should be considered as one of the instruments to reach the Health in All Policies (HiAP) goals.

Adverse working conditions and immigrants' physical health and depression outcomes: a longitudinal study in Greece

PURPOSE

Τhe study examines whether adverse working conditions for immigrants in Greece bear an association with deteriorated physical health and increased levels of depression during 2018 and 2019.

METHODS

A panel dataset resulted from the collaboration with centers providing free Greek language courses to immigrant population groups. Random Effects models assess the determinants of physical health and depression.

RESULTS

Findings indicate that workers with no written contract of employment, receiving hourly wages lower than the national hourly minimum wages, and experiencing insults and/or threats in their present job experience worse physical health and increased levels of depression. Moreover, the study found that the inexistence of workplace contracts, underpayment, and verbal abuse in the workplace may coexist. An increased risk of underpayment and verbal abuse reveals itself when workers do not have a contract of employment and vice versa.

CONCLUSION

Immigrant workers without a job contract might experience a high degree of workplace precariousness and exclusion from health benefits and insurance. Immigrant workers receiving a wage lower than the corresponding minimum potentially do not secure a living income, resulting in unmet needs and low investments in health. Workplace abuse might correspond with vulnerability related to humiliating treatment. These conditions can negatively impact workers' physical health and foster depression. Policies should promote written employment contracts and ensure a mechanism for workers to register violations of fair practices.

The effect of income-based policies on mortality inequalities in Scotland: a modelling study

BACKGROUND

The unequal distribution of income is a fundamental determinant of health inequalities. Decision making around economic policies could be enhanced by showing their potential health effects. We used scenario modelling to assess the effects of 12 income-based policies on years of life lost (YLL) and inequalities in YLL in Scotland for the 2017-21 period.

METHODS

In this modelling study, we used EUROMOD version H1.0+, a tax-benefit microsimulation model, to estimate the effects of hypothetical fiscal policies on household income for Scottish households in the 2014/15 Family Resources Survey (n=2871). The effects were modelled excluding housing costs. Income change from baseline was estimated for each quintile of the 2016 Scottish Index of Multiple Deprivation (SIMD) after weighting to account for differential non-response to the Family Resources Survey, and incomes were equivalised according to the Organisation for Economic Co-operation and Development's modified equivalence scale. A regression analysis of cross-sectional data was used to estimate the relationship between income change and all-cause mortality, followed up by a sensitivity analysis to account for uncertainties around the assumptions on effect size. Informing Interventions to reduce health Inequalities (Triple I), a health inequalities scenario modelling tool, was used to estimate policy effects on YLL and government spending after five years of theoretical implementation. The Triple I model used population estimates for 2016 stratified by sex, 5-year age group, and SIMD quintile, which were obtained from the National Records of Scotland. Preliminary estimates of relative policy costs were calculated from the EUROMOD-derived combined effects of each policy on tax bills, National Insurance contributions, and benefits receipts for Scottish households.

FINDINGS

Taxation-based policies did not substantially affect household incomes, whereas benefits-based policies had large effects across the quintiles. The best policy for improving health and narrowing health inequalities was a 50% increase to means-tested benefits (approximately 105 177 [4·7%] YLL fewer than the baseline of 2·2 million, and a 7·9% reduction in relative index of inequality). Effects on YLL and health inequalities were inversely correlated in response to changes in taxation policy. Citizen's Basic Income (CBI) schemes also substantially narrowed inequalities (3·7% relative index of inequality for basic scheme, 5·9% for CBI with additional payments for individuals with disability), and modestly reduced YLL (0·7% for the basic scheme and 1·4% with additional payments). The estimated government spending associated with a policy was proportional to its effect on YLL, but less closely related to its effect on inequalities in YLL.

INTERPRETATION

Policies that affect incomes could potentially have marked effects on health and health inequalities in Scotland. Our projections suggest that the most effective policies for reducing health inequalities appeared to be those that disproportionately increased incomes in the most deprived areas. Although modelling was subject to various assumptions, the approach can be useful to inform decisions around addressing the upstream determinants of health inequalities.

FUNDING

None.

Minimum wages and public health: A literature review

We evaluate evidence for the effectiveness of raising minimum wages on various measures of public health within the US, Canada, the UK, and Europe. We search four scientific websites from the inception of the research through May 20, 2018. We find great variety (20+) in measured outcomes among the 33 studies that pass our initial screening. We establish quality standards in a second screening resulting in 15 studies in which we create outcome-based groups. Outcomes include four broad measures (general overall health, behavior, mental health, and birth weight) and eight narrow measures (self-reported health, "bad" health days, unmet medical need, smoking, problem-drinking, obesity, eating vegetables, and exercise). We establish criteria for "stronger" findings for outcomes and methods. Stronger findings include: $1 increases in minimum wages are associated with 1.4 percentage point (4% evaluated at mean) decreases in smoking prevalence; failure to reject null hypotheses that minimum wages have no effects for most outcomes; and no consistent evidence that minimum wages harm health. One "suggestive" finding is that the best-designed studies have well-defined treatment (or likely affected) and control (unaffected) groups and contain longitudinal data. The major methodological weaknesses afflicting many studies are the lack of focus on persons likely affected by minimum wages and omission of "falsification tests" on persons likely unaffected. An additional weakness is lack of attention to how findings might differ across populations such as teenagers, adults, men, women, continuously employed and unemployed persons. Research into health effects of minimum wages is in its infancy and growing rapidly. We present a list of "better practices" for future research.

Economic Vulnerability Among US Female Health Care Workers: Potential Impact of a $15-per-Hour Minimum Wage

OBJECTIVES

To investigate racial/ethnic and gender inequities in the compensation and benefits of US health care workers and assess the potential impact of a $15-per-hour minimum wage on their economic well-being.

METHODS

Using the 2017 Annual Social and Economic Supplement to the Current Population Survey, we compared earnings, insurance coverage, public benefits usage, and occupational distribution of male and female health care workers of different races/ethnicities. We modeled the impact of raising the minimum wage to $15 per hour with different scenarios for labor demand.

RESULTS

Of female health care workers, 34.9% of earned less than $15 per hour. Nearly half of Black and Latina female health care workers earned less than $15 per hour, and more than 10% lacked health insurance. A total of 1.7 million female health care workers and their children lived in poverty. Raising the minimum wage to $15 per hour would reduce poverty rates among female health care workers by 27.1% to 50.3%.

CONCLUSIONS

Many US female health care workers, particularly women of color, suffer economic privation and lack health insurance. Achieving economic, gender, and racial/ethnic justice will require significant changes to the compensation structure of health care.

Evaluating Structural Change Approaches to Health Promotion: An Exploratory Scoping Review of a Decade of U.S. Progress

Structural change approaches—also known as policy and environmental changes—are becoming increasingly common in health promotion, yet our understanding of how to evaluate them is still limited. An exploratory scoping review of the literature was conducted to understand approaches and methods used to evaluate structural change interventions in health promotion and public health literature. Two analysts—along with health sciences librarian consultation—searched PubMed, Web of Science, and EMBASE for peer-reviewed U.S.-based, English language studies published between 2005 and 2016. Data were extracted on the use of evaluation frameworks, study designs, duration of evaluations, measurement levels, and measurement types. Forty-five articles were included for the review. Notably, the majority (73%) of studies did not report application of a specific evaluation framework. Studies used a wide range of designs, including process evaluations, quasi- or nonexperimental designs, and purely descriptive approaches. In addition, 15.6% of studies only measured outcomes at the individual level. Last, 60% of studies combined more than one measurement type (e.g., site observation + focus groups) to evaluate interventions. Future directions for evaluating structural change approaches to health promotion include more widespread use and reporting of evaluation frameworks, developing validated tools that measure structural change, and shifting the focus to health-directed approaches, including an expanded consideration for evaluation designs that address health inequities.

Cross-sectional analysis of two social determinants of health in California cities: racial/ethnic and geographic disparities

OBJECTIVE

To study the magnitude and direction of city-level racial and ethnic differences in poverty and education to characterise health equity and social determinants of health in California cities.

DESIGN

We used data from the American Community Survey, United States Census Bureau, 2006-2010, and calculated differences in the prevalence of poverty and low educational attainment in adults by race/ethnicity and by census tracts within California cities. For race/ethnicity comparisons, when the referent group (p2) to calculate the difference (p1-p2) was the non-Hispanic White population (considered a historically advantaged group), a positive difference was considered a health inequity. Differences with a non-White reference group were considered health disparities.

SETTING

Cities of the State of California, USA.

RESULTS

Within-city differences in the prevalence of poverty and low educational attainment disfavoured Black and Latinos compared with Whites in over 78% of the cities. Compared with Whites, the median within-city poverty difference was 7.0% for Latinos and 6.2% for Blacks. For education, median within-city difference was 26.6% for Latinos compared with Whites. In a small, but not negligible proportion of cities, historically disadvantaged race/ethnicity groups had better social determinants of health outcomes than Whites. The median difference between the highest and lowest census tracts within cities was 14.3% for poverty and 15.7% for low educational attainment. Overall city poverty rate was weakly, but positively correlated with within-city racial/ethnic differences.

CONCLUSIONS

Disparities and inequities are widespread in California. Local health departments can use these findings to partner with cities in their jurisdiction and design strategies to reduce racial, ethnic and geographic differences in economic and educational outcomes. These analytic methods could be used in an ongoing surveillance system to monitor these determinants of health.

Effectiveness of Health Impact Assessments: A Synthesis of Data From Five Impact Evaluation Reports

Introduction

Since the 1990s, the use of health impact assessments (HIAs) has grown for considering the potential health impacts of proposed policies, plans, programs, and projects in various sectors. Evaluation of HIA impacts is needed for understanding the value of HIAs, improving the methods involved in HIAs, and potentially expanding their application. Impact evaluations examine whether HIAs affect decisions and lead to other effects.

Methods

I reviewed HIA impact evaluations identified by literature review and professional networking. I abstracted and synthesized data on key findings, success factors, and challenges from 5 large evaluations conducted in the United States, Europe, Australia, and New Zealand and published from 2006 through 2015. These studies analyzed impacts of approximately 200 individual HIAs.

Results

Major impacts of HIAs were directly influencing some decisions, improving collaboration among stakeholders, increasing awareness of health issues among decision makers, and giving community members a stronger voice in local decisions. Factors that contributed to successful HIAs included engaging stakeholders, timeliness, policy and systems support for conducting HIAs, having people with appropriate skills on the HIA team, obtaining the support of decision makers, and providing clearly articulated, feasible recommendations. Challenges that may have reduced HIA success were poor timeliness, underestimation of time and resources needed, difficulty in accessing relevant data, use of jargon in HIA reports, difficulty in involving decision makers in the HIA process, and absence of a requirement to conduct HIAs.

Conclusion

HIAs can be useful to promote health and mitigate adverse impacts of decisions made outside of the health sector. Stakeholder interactions and community engagement may be as important as direct impacts of HIAs. Multiple factors are required for HIA success. Further work could strengthen the role of HIAs in promoting equity, examine HIA impacts in specific sectors, and document the role of HIAs in a “health in all policies” approach.

Estimating Potential Reductions in Premature Mortality in New York City From Raising the Minimum Wage to $15

OBJECTIVES

To assess potential reductions in premature mortality that could have been achieved in 2008 to 2012 if the minimum wage had been $15 per hour in New York City.

METHODS

Using the 2008 to 2012 American Community Survey, we performed simulations to assess how the proportion of low-income residents in each neighborhood might change with a hypothetical $15 minimum wage under alternative assumptions of labor market dynamics. We developed an ecological model of premature death to determine the differences between the levels of premature mortality as predicted by the actual proportions of low-income residents in 2008 to 2012 and the levels predicted by the proportions of low-income residents under a hypothetical $15 minimum wage.

RESULTS

A $15 minimum wage could have averted 2800 to 5500 premature deaths between 2008 and 2012 in New York City, representing 4% to 8% of total premature deaths in that period. Most of these avertable deaths would be realized in lower-income communities, in which residents are predominantly people of color.

CONCLUSIONS

A higher minimum wage may have substantial positive effects on health and should be considered as an instrument to address health disparities.

New Approaches for Moving Upstream

Growing evidence shows that unequal distribution of wealth and power across race, class, and gender produces the differences in living conditions that are “upstream” drivers of health inequalities. Health educators and other public health professionals, however, still develop interventions that focus mainly on “downstream” behavioral risks. Three factors explain the difficulty in translating this knowledge into practice. First, in their allegiance to the status quo, powerful elites often resist upstream policies and programs that redistribute wealth and power. Second, public health practice is often grounded in dominant biomedical and behavioral paradigms, and health departments also face legal and political limits on expanding their scope of activities. Finally, the evidence for the impact of upstream interventions is limited, in part because methodologies for evaluating upstream interventions are less developed. To illustrate strategies to overcome these obstacles, we profile recent campaigns in the United States to enact living wages, prevent mortgage foreclosures, and reduce exposure to air pollution. We then examine how health educators working in state and local health departments can transform their practice to contribute to campaigns that reallocate the wealth and power that shape the living conditions that determine health and health inequalities. We also consider health educators’ role in producing the evidence that can guide transformative expansion of upstream interventions to reduce health inequalities.

Structural Approaches to Health Promotion

Although the public health literature has increasingly called on practitioners to implement changes to social, environmental, and political structures as a means of improving population health, recent research suggests that articles evaluating organization, community, or policy changes are more limited than those focused on programs with individuals or their social networks. Even when these approaches appear promising, we do not fully understand whether they will benefit all population groups or can be successful in the absence of accompanying individually oriented programs. The role of this broad category of approaches, including both policy and environmental changes, in decreasing health disparities is also unclear, often benefiting some communities more than others. Finally, the political nature of policy and environmental change, including the impact on personal autonomy, raises questions about the appropriate role for public health professionals in advancing specific policies and practices that alter the conditions in which people live. This article addresses these issues and ends with a series of questions about the effectiveness and ethical implementation of what we have termed “structural initiatives.”

Investigating the effect of the London living wage on the psychological wellbeing of low-wage service sector employees: a feasibility study

BACKGROUND

Working poverty has become a major public health concern in recent times, and low-paid, insecure employment has been widely linked to poor psychological wellbeing. The London Living Wage (LLW) campaign aims to ensure employees receive adequate pay. The objective of this study is to investigate whether working for a LLW employer predicted higher levels of psychological wellbeing among low-wage service sector employees.

METHODS

Workplace interviews were conducted with 300 service sector employees in London; 173 of whom were in LLW workplaces. Positive psychological wellbeing was measured using the Warwick-Edinburgh Mental Wellbeing Scale. Multivariate linear regression was used to assess whether working for a LLW employer was associated with greater psychological wellbeing, adjusting for hypothesised confounding and mediating factors.

RESULTS

After adjustment, respondents working for LLW employers had wellbeing scores 3.9 units higher on average than those who did not (95% CI: 1.8, 6.0). These empirical results are complemented by methodological findings regarding the difficulties associated with accessing the study group.

CONCLUSIONS

Those who worked for a LLW employer had significantly higher psychological wellbeing on average than those who did not. This was shown to be irrespective of any differences in the socioeconomic or demographic composition of these two groups.

The DYNAMO-HIA Model: An Efficient Implementation of a Risk Factor/Chronic Disease Markov Model for Use in Health Impact Assessment (HIA)

In Health Impact Assessment (HIA), or priority-setting for health policy, effects of risk factors (exposures) on health need to be modeled, such as with a Markov model, in which exposure influences mortality and disease incidence rates. Because many risk factors are related to a variety of chronic diseases, these Markov models potentially contain a large number of states (risk factor and disease combinations), providing a challenge both technically (keeping down execution time and memory use) and practically (estimating the model parameters and retaining transparency). To meet this challenge, we propose an approach that combines micro-simulation of the exposure information with macro-simulation of the diseases and survival. This approach allows users to simulate exposure in detail while avoiding the need for large simulated populations because of the relative rareness of chronic disease events. Further efficiency is gained by splitting the disease state space into smaller spaces, each of which contains a cluster of diseases that is independent of the other clusters. The challenge of feasible input data requirements is met by including parameter calculation routines, which use marginal population data to estimate the transitions between states. As an illustration, we present the recently developed model DYNAMO-HIA (DYNAMIC MODEL for Health Impact Assessment) that implements this approach.

DYNAMO-HIA--a Dynamic Modeling tool for generic Health Impact Assessments

BACKGROUND

Currently, no standard tool is publicly available that allows researchers or policy-makers to quantify the impact of policies using epidemiological evidence within the causal framework of Health Impact Assessment (HIA). A standard tool should comply with three technical criteria (real-life population, dynamic projection, explicit risk-factor states) and three usability criteria (modest data requirements, rich model output, generally accessible) to be useful in the applied setting of HIA. With DYNAMO-HIA (Dynamic Modeling for Health Impact Assessment), we introduce such a generic software tool specifically designed to facilitate quantification in the assessment of the health impacts of policies.

METHODS AND RESULTS

DYNAMO-HIA quantifies the impact of user-specified risk-factor changes on multiple diseases and in turn on overall population health, comparing one reference scenario with one or more intervention scenarios. The Markov-based modeling approach allows for explicit risk-factor states and simulation of a real-life population. A built-in parameter estimation module ensures that only standard population-level epidemiological evidence is required, i.e. data on incidence, prevalence, relative risks, and mortality. DYNAMO-HIA provides a rich output of summary measures--e.g. life expectancy and disease-free life expectancy--and detailed data--e.g. prevalences and mortality/survival rates--by age, sex, and risk-factor status over time. DYNAMO-HIA is controlled via a graphical user interface and is publicly available from the internet, ensuring general accessibility. We illustrate the use of DYNAMO-HIA with two example applications: a policy causing an overall increase in alcohol consumption and quantifying the disease-burden of smoking.

CONCLUSION

By combining modest data needs with general accessibility and user friendliness within the causal framework of HIA, DYNAMO-HIA is a potential standard tool for health impact assessment based on epidemiologic evidence.

Promoting health and safety in San Francisco's Chinatown restaurants: findings and lessons learned from a pilot observational checklist

Noncompliance with labor and occupational health and safety laws contributes to economic and health inequities. Environmental health agencies are well positioned to monitor workplace conditions in many industries and support enhanced enforcement by responsible regulatory agencies. In collaboration with university and community partners, the San Francisco Department of Public Health used an observational checklist to assess preventable occupational injury hazards and compliance with employee notification requirements in 106 restaurants in San Francisco's Chinatown. Sixty-five percent of restaurants had not posted required minimum wage, paid sick leave, or workers' compensation notifications; 82% of restaurants lacked fully stocked first-aid kits; 52% lacked antislip mats; 37% lacked adequate ventilation; and 28% lacked adequate lighting. Supported by a larger community-based participatory research process, this pilot project helped to spur additional innovative health department collaborations to promote healthier workplaces.

Standard tool for quantification in health impact assessment a review

BACKGROUND

The health impact assessment (HIA) of policy proposals is becoming common practice. HIA represents a broad approach with quantification of the impact of policy options at its core. However, no standard tool is available and it remains unclear whether any current model can serve as a standard for the field.

PURPOSE

The aim of this study is to assess whether already existing models can be used as a standard tool for the quantification step in an HIA.

METHODS

A search in 2008 identified 20 models for HIA, of which six are sufficiently generic to allow for various and multiple diseases and different risk factors: Age-Related Morbidity and Death Analysis, Global Burden of Disease, Population Health Modeling, PREVENT, Proportional Life Table Method, and the National Institute for Public Health and the Environment (the Netherlands) Chronic Disease Model. These were evaluated along three proposed model structure criteria (real-life population, dynamic projection, explicit risk-factor states) and three usability criteria (modest data requirements, rich model output, generally accessible) developed to address the needs and requirements of the HIA framework.

RESULTS

Of the six generic models investigated, none fulfills all the proposed criteria as a standard HIA tool. The models are either technically advanced with no or limited accessibility, or they are accessible but oversimplified.

CONCLUSIONS

Further work on models for HIA with equal emphasis on technical appropriateness, availability of data, and end-user-friendly implementation is warranted if the field is to move forward.

Evidence-based public health: a fundamental concept for public health practice

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.

Use of health impact assessment in the U.S.: 27 case studies, 1999-2007

OBJECTIVES

To document the growing use in the United States of health impact assessment (HIA) methods to help planners and others consider the health consequences of their decisions.

METHODS

Using multiple search strategies, 27 HIAs were identified that were completed in the U.S. during 1999-2007. Key characteristics of each HIA were abstracted from published and unpublished sources.

RESULTS

Topics examined in these HIAs ranged from policies about living wages and after-school programs to projects about power plants and public transit. Most HIAs were funded by local health departments, foundations, or federal agencies. Concerns about health disparities were especially important in HIAs on housing, urban redevelopment, home energy subsidies, and wage policy. The use of quantitative and nonquantitative methods varied among HIAs. Most HIAs presented recommendations for policy or project changes to improve health. Impacts of the HIAs were infrequently documented.

CONCLUSIONS

These completed HIAs are useful for helping conduct future HIAs and for training public health officials and others about HIAs. More work is needed to document the impact of HIAs and thereby increase their value in decision-making processes.

Health impact assessment: a tool to help policy makers understand health beyond health care

Health impact assessment (HIA)--a combination of methods to examine formally the potential health effects of a proposed policy, program, or project--has received considerable interest over the past decade internationally as a practical mechanism for collaborating with other sectors to address the environmental determinants of health and to achieve more effectively the goals of population health promotion. Demand for HIA in the United States seems to be growing. This review outlines the common principles and methodologies of HIA and compares different approaches to HIA. Lessons learned from the related field of environmental impact assessment and from experience with HIA in other countries are examined. Possible avenues for advancing both the field and the broader goals of population health promotion are outlined.

Promoting evidence-based public health policy: can we have better evidence and more action?

Evidence-based approaches (those explicitly linked to the best available scientific evidence and reflecting community preferences and feasibility) are increasingly used to inform health policy decision making on the burden of a disease attributable to particular causes, interventions and policies that might work to confront those causes, and issues of community fit and feasibility. This paper introduces several tools for evidence-based public health: the health impact assessment, the systematic review, and a portfolio for assuring community fit and feasibility. Discussion of these tools serves as a springboard to consider how to better bring scientific evidence to bear on real-life health issues.

Shifting dollars, saving lives: What might happen to mortality rates, and socio-economic inequalities in mortality rates, if income was redistributed?

Personal or household income predicts mortality risk, with each additional dollar of income conferring a slightly smaller decrease in the mortality risk. Regardless of whether levels of income inequality in a society impact on mortality rates over and above this individual-level association (i.e., the 'income inequality hypothesis'), the current consensus is that narrowing income distributions will probably improve overall health status and reduce socio-economic inequalities in health. Our objective was to quantify this impact in a national population using 1.3 million 25-59-year-old respondents to the New Zealand 1996 census followed-up for mortality over 3 years. We modelled 10-40% shifts of everyone's income to the mean income (equivalent to 10-40% reductions in the Gini coefficient). The strength of the income-mortality association was modelled using rate ratios from Poisson regression of mortality on the logarithm of equivalised household income, adjusted for confounders of age, marital status, education, car access, and neighbourhood socio-economic deprivation. Overall mortality reduced by 4-13% following 10-40% shifts in everyone's income, respectively. Inequalities in mortality reduced by 12-38% following 10-40% shifts in everyone's income. Sensitivity analyses suggested that halving the strength of the income-mortality association (i.e., assuming our multivariable estimate still overestimated the causal income-mortality association) would result in 2-6% reductions in overall mortality and 6-19% reductions in inequalities in mortality in this New Zealand setting. Many commentators have noted the non-linear association of income with mortality predicts that narrowing the income distribution will both reduce overall mortality rates and reduce inequalities in mortality. Quantifying such reductions can only be done with considerable uncertainty. Nevertheless, we tentatively suggest that the gains in overall mortality will be modest (although still potentially worthwhile from a policy perspective) and the reductions in inequalities in mortality will be more substantial.

Researchers and policymakers: travelers in parallel universes

Public policy, in the form of laws, guidelines, and regulations, has a profound effect on our daily lives and health status. Reasons for a lack of consistent and systematic translation of public health research into public policy is examined, including differences in decision-making processes, poor timing, ambiguous findings, the need to balance objectivity and advocacy, personal demands of the process, information overload, lack of relevant data, and the mismatch of randomized thinking with nonrandom problems. Next, several actions are suggested that should help bridge the chasm between science and policy, such as greater involvement in the process, better understanding of political decision making, building of effective teams, and development of political champions. Scientists are obligated not only to discover new knowledge but also to ensure that discoveries are applied to improve health.

Growing the field of health impact assessment in the United States: an agenda for research and practice

Health impact assessment (HIA) methods are used to evaluate the impact on health of policies and projects in community design, transportation planning, and other areas outside traditional public health concerns. At an October 2004 workshop, domestic and international experts explored issues associated with advancing the use of HIA methods by local health departments, planning commissions, and other decisionmakers in the United States. Workshop participants recommended conducting pilot tests of existing HIA tools, developing a database of health impacts of common projects and policies, developing resources for HIA use, building workforce capacity to conduct HIAs, and evaluating HIAs. HIA methods can influence decisionmakers to adjust policies and projects to maximize benefits and minimize harm to the public's health.