Individuals from different backgrounds, social groups, and countries enjoy different levels of health. This article defines and distinguishes between unavoidable health inequalities and unjust and preventable health inequities. We describe the dimensions along which health inequalities are commonly examined, including across the global population, between countries or states, and within geographies, by socially relevant groupings such as race/ethnicity, gender, education, caste, income, occupation, and more. Different theories attempt to explain group-level differences in health, including psychosocial, material deprivation, health behavior, environmental, and selection explanations. Concepts of relative versus absolute; dose–response versus threshold; composition versus context; place versus space; the life course perspective on health; causal pathways to health; conditional health effects; and group-level versus individual differences are vital in understanding health inequalities. We close by reflecting on what conditions make health inequalities unjust, and to consider the merits of policies that prioritize the elimination of health disparities versus those that focus on raising the overall standard of health in a population.

Neighborhood effects on health research has grown over the past 20 years. While the substantive findings of this literature have been published in systematic reviews, meta-analyses, and commentaries, operational details of the research have been understudied. We identified 7,140 multi-level neighborhoods and health papers published on US populations between 1995–2014, and present data on the study characteristics of the 259 papers that met our inclusion criteria. Our results reveal rapid growth in neighborhoods and health research in the mid-2000s, illustrate the dominance of observational cross-sectional study designs, and show a heavy reliance on single-level, census-based neighborhood definitions. Socioeconomic indicators were the most commonly analyzed neighborhood variables and body mass was the most commonly studied health outcome. Well-known challenges associated with neighborhood effects research were infrequently acknowledged. We discuss how these results move the agenda forward for neighborhoods and health research.

In the 1930s, maps created by the federal Home Owners’ Loan Corporation (HOLC) nationalized residential racial segregation via “redlining,” whereby HOLC designated and colored in red areas they deemed to be unsuitable for mortgage lending on account of their black, foreign-born, or low-income residents. We used the recently digitized HOLC redlining maps for 28 municipalities in Massachusetts to analyze Massachusetts Cancer Registry data for late stage at diagnosis for cervical, breast, lung, and colorectal cancer (2001–2015). Multivariable analyses indicated that, net of age, sex/gender, and race/ethnicity, residing in a previously HOLC-redlined area imposed an elevated risk for late stage at diagnosis, even for residents of census tracts with present-day economic and racial privilege, whereas the best historical HOLC grade was not protective for residents of census tracts without such current privilege. For example, a substantially elevated risk of late stage at diagnosis occurred among men with lung cancer residing in currently privileged areas that had been redlined (risk ratio = 1.17, 95% confidence interval: 1.06, 1.29), whereas such risk was attenuated among men residing in census tracts lacking such current privilege (risk ratio = 1.01, 95% confidence interval: 0.94, 1.08). Research on historical redlining as a structural driver of health inequities is warranted.

Despite a proliferation of research on neighborhood effects on health, how neighborhood economic development, in the form of gentrification, affects health and well-being in the U.S. is poorly understood, and no systematic assessment of the potential health impacts has been conducted. Further, we know little about whether health impacts differ for residents of neighborhoods undergoing gentrification versus urban development, or other forms of neighborhood socioeconomic ascent. We followed current guidelines for systematic reviews and present data on the study characteristics of the twenty-two empirical articles that met our inclusion criteria and were published on associations between gentrification, and similar but differently termed processes (e.g., urban regeneration, urban development, neighborhood upgrading), and health published between 2000 and 2018. Our results show that impacts on health vary by outcome assessed, exposure measurement, the larger context specific determinants of neighborhood change, and analysis decisions including which reference and treatment groups to examine. Studies of the health impacts of gentrification, urban development, and urban regeneration describe similar processes, and synthesis and comparison of their results helps bridge differing theoretical approaches to this emerging research. Our article helps to inform the debate on the impacts of gentrification and urban development for health and suggests that these neighborhood change processes likely have both detrimental and beneficial effects on health. Given the influence of place on health and the trend of increasing gentrification and urban development in many American cities, we discuss how future research can approach understanding and researching the impacts of these processes for population health.

In August 2005, Hurricane Katrina caused unprecedented damage, widespread population displacement, and exposed Gulf Coast residents to traumatic events. The hurricane's adverse impact on survivors' mental health was apparent shortly after the storm and persisted, but no study has examined the long-term effects now that more than a decade has transpired. Using new data from a panel study of low-income mothers interviewed once before Hurricane Katrina and now three times after, we document changes in mental health, and estimate the sociodemographic and hurricane-related factors associated with long-term trajectories of mental health. We find that post-traumatic stress symptoms (PTSS) declined at each of the three post-Katrina follow-ups, but 12 years after the hurricane, one in six still had symptoms indicative of probable post-traumatic stress disorder. The rate of non-specific psychological distress (PD) remained consistently higher in all three follow-ups, compared to the pre-disaster period. In full covariate-adjusted models, no sociodemographic variables predicted long-run combinations of PTSS and PD. However, 12 years later, exposure to hurricane-related traumatic events and pre-disaster PD significantly predicted co occurring PTSS and PD. Hurricane-related housing damage predicted PTSS in earlier follow-ups, but no longer predicted PTSS in the long-term. Furthermore, hurricane-related traumatic events significantly differentiated the risk of having persistent PTSS, relative to recovering from PTSS.