Population vulnerabilities and capacities related to health: a test of a model.

Variability in the health of human populations is greater in economically vulnerable areas. We tested whether this variability reflects and can be explained by: (1) underlying vulnerabilities and capacities of populations and/or (2) differences in the distribution of individual socioeconomic status between populations. Health outcomes were rates of mortality from 12 causes (cardiovascular disease, malignant neoplasms, accidents, chronic lower respiratory disease, cerebrovascular disease, pneumonia and influenza, diseases of the nervous system, suicide, chronic liver disease and cirrhosis, diabetes, homicide, HIV/AIDS) for 59 New York City neighborhoods in 2000. Negative binomial regression models were fit with a measure of socioeconomic vulnerability, median income, predicting each mortality rate. Overdispersion of each model was used to assess whether variability in mortality rates increased with increasing neighborhood socioeconomic vulnerability. To assess the two hypotheses, we examined changes in the variability of mortality rates (as indicated by changes in overdispersion of the models) for outcomes with significant non-constant variability after accounting for (1) vulnerabilities and capacities (social control, quality of local schools, unemployment, low education), and (2) the distribution of individual socioeconomic status (low income, poverty, socioeconomic distribution, high income). Some variability in all mortality rates was explained by accounting for a range of potential vulnerabilities and capacities, supporting the first explanation. However, variability in some causes of mortality was also explained in part by accounting for the distribution of individual resources, supporting the second explanation. The results are consistent with a theory of underlying socioeconomic vulnerabilities of human populations. In areas with lower levels of income, other characteristics of those neighborhoods exacerbate or temper the economic vulnerability, leading to more or less healthy conditions. Understanding the vulnerabilities and capacities that characterize populations may help us better understand the production of population health, and may inform efforts aimed at improving population health.