The source of data is represented by The Big Cities Health Coalition (BCHC), a forum for the leaders of America’s largest metropolitan health departments to exchange strategies and jointly address issues to promote and protect the health and safety of the people they serve. BCHC is a project of the National Association of County and City Health Officials (NACCHO), which represents the nation’s 2,800 local governmental health departments.
Most of the data came directly from cities, while some were secured from the U.S. Census or other similar publicly available dataset where city data were available. For the most part, jurisdictions reported their three most recent years of data, which were 2012, 2013, and 2014. Data prior to 2010 were not included, even if it meant a jurisdiction only had two years of data available. The nature of the data varies considerably. When data were not provided or available, the appropriate cell was left blank. Not all health departments were able to provide data for all indicators and, in cases where denominators were too small, certain rates for subpopulations were not displayed.
Most data were reviewed by individual cities as well. Where sample sizes allow, indicators are broken down into subpopulations for race and ethnicity categories. For most jurisdictions, the default options were White (Non-Hispanic), Black (Non-Hispanic), Hispanic, Asian/Pacific Islander, American Indian/Alaska Native, and Other. In areas where certain populations were too small, the various subpopulations were included in the “other” category with any additional racial/ethnic minorities. In many of the California cities, as well as Seattle, reported numbers only represent Asians; Pacific Islanders are not included. Some jurisdictions also report mixed-race numbers, and where they do, those numbers are reported as “Multi-racial”.
The health risk or protection factors for which prevalence level estimated values are included, are as follows:
– health risk factors: binge-drinking, obesity and cigarette smoking;
– health protection factors: physical activity level according to CDC recommendations.
Although the health risk and health protection factors are generally denominated briefly health risk factors, in order to underline the fact that physical activity level assessment determined the number of persons which are compliant with the CDC recommendations (and not the persons who are not compliant), the denomination used for the dataset in this case is more detailed and it specifies that includes a health protection factor. Exposure to a health protection factor has a positive effect on health.
The percentage of adults who binge drank is based (in most cases) on the Behavioral Risk Factor Surveillance System. (BRFSS) question about how many drinks a person had on one occasion in the past 30 days. Women who answered “four” and men who answered “five” are considered binge drinkers. Similarly, percent of high school students who binge drank is based (in most cases) on the Youth Risk Behavior Surveillance System (YRBS/YRBSS) question regarding five or more drinks within a couple hours on one or more occasions in the past 30 days. As with other indicators, if BRFSS or YRBS/YRBSS data were not available, a comparable survey was used, or the data were left out if not completely comparable.
Where possible, the adult obesity figure in this report is the percentage of the population 18 years or over that is considered obese, generally with a body mass index (BMI) of 30 or above, and in most cases is taken from BRFSS. Similarly, obesity rates for children are difficult to collect, though many jurisdictions know the percent of high school students that are obese, particularly in large urban school districts. In children, the definition is a BMI at or above the 95th percentile of children of the same age or sex. Physical activity data were taken from BRFSS or YRBS/YRBSS based on CDC-recommended activity levels. For adults: at least 2 hours, 30 minutes of moderate-intensity aerobic activity every week for good health; 1 hour, 15 minutes of vigorous-intensity aerobic activity; or an equivalent mix of moderate and vigorous. For high school students: physically active for a total of at least 60 minutes per day. Where possible, this publication relied on BRFSS or YRBS/YRBSS so that data were comparable. In most cases, if data were not comparable, they were excluded.
Data on cigarette use among both adults (over 18 years of age) and youth (for the most part, high school students) are also hard to obtain at the city level. The most frequently used sources of data are the BRFSS, the Youth Risk Behavioral Survey (YRBS), or the Youth Risk Behavioral Surveillance System (YRBSS). Many cities/counties oversample to have accurate data for the jurisdictions, but some do not. Sample sizes vary, as do years of data available. Youth tobacco numbers were included only if they were secured via YRBS or YRBSS or a comparable survey, both in terms of population (high school students) and question text. Readers should take note of both source and year of data availability when using the tobacco- related data in this publication.
Dataset contains the BCHC requested methodology for every indicator, along with sources of data used by the BCHC member and notes about the methods and data.