Human health can be affected by many varying environmental and social factors. Numerous studies have shown an association between transportation, air pollution, and adverse human health effects. Asthma exacerbation and other respiratory illnesses have been linked to human exposure to fine particulate matter (PM), as well as polycyclic aromatic hydrocarbons (PAHs) found in petroleum fuels. PM2.5 is particularly dangerous as it is directly emitted by combustion of fossil fuels and is also produced by secondary formation of sulfur dioxide and nitrogen oxide emissions. This direct link to fossil fuels and the growing evidence of the built environment's effect on physical activity and equitable access to resources are what drive DVRPC and other government agencies to develop policy to recognize the human health aspects of transportation and land use planning. To learn more about air pollution and DVRPC's programs to address air quality, please see: www.dvrpc.org/AirQuality.
To that end, DVRPC produced a brief data analysis to better understand the geographic distribution of health outcomes. The data used in this analysis are from Public Health Management Corporation's (PHMC) Community Health Data Base (CHDB) 2010 Southeastern Pennsylvania Household Health Survey. Maps, data descriptions, and a Health Disparity Index [0.2 MB pdf] are presented in web format to inform DVRPC staff and others.
The Household Health Survey is a random digit dial telephone survey of over 10,000 households in the southeastern Pennsylvania region of Bucks, Chester, Delaware, Montgomery, and Philadelphia counties. Telephone interviews, including landline and wireless interviews, are conducted with over 10,000 adults 18 years of age or older and an additional 2,700 interviews are conducted about a selected child in the household; the survey also includes an oversample of older adults. The survey provides information on a broad range of self-reported health topics, including health status, access to and use of healthcare services, personal health behaviors, and health screenings. Household Health Survey data are available at the ZIP code, census tract, county, neighborhood, and regional levels. PHMC weights the data by race, age, sex, household size, and income to adjust for sampling bias commonly found in telephone surveys. DVRPC aggregated data up to a "planning area" to reach a sample size of at least 50 respondents per question per geography.
Selected Health Outcome Indicators
Figure 1.1 - PHMC Suburban Planning Regions and Philadelphia Planning Analysis Sections
Multiple studies have linked low-density development to less physical activity, and consequently, to higher rates of obesity, diabetes, and cardiovascular disease.
- Low-density development leads to increased use of automobiles rather than walking, biking, or taking transit (which typically also requires more walking between destinations than auto use).
- Health effects related to traffic congestion stem from increased air pollution.
- A number of studies have established that land use determines primary mode of travel, and certain neighborhoods have physical and socio-economic conditions that make them more walkable or bikeable.
- There is growing evidence that physical activity tied to daily behavior, for example biking to work or walking to accomplish errands, has health benefits such as reduced weight and improved cardio-fitness, which protects against cardiovascular disease.
DVRPC selected four health-related indicators to review based on the Commission's comprehensive planning goals.
- "Overweight and Obesity" was selected as an indicator because it can signify other chronic health issues and is partially related to behavior.
- "Asthma" was selected as an indicator because of direct links between outdoor air quality, traffic congestion, burning of fossil fuels, and rising incidence of asthma among many different population groups.
- "Diabetes" was selected as an indicator as it is a chronic disease in increasing in prevalence, and due to its connection to maintaining healthy diet and physical activity throughout a lifetime.
- Similarly, "High Blood Pressure" was selected as an indicator as it is related to eating a healthy diet, staying active and maintaining a healthy weight throughout a lifetime.
Of the four indicators, data was analyzed by age group – adults (persons over 18), Elderly and near elderly (adults 60+), and children (persons under 18), if applicable. Survey responses were aggregated up to "planning regions" in order to capture at least 50 respondents, the threshold determined (by PHMC) to be statistically significant. Southeastern Pennsylvania is divided into 31 suburban planning regions and Philadelphia planning analysis sections. A mean threshold was established for each health indicator and age group to identify geographic areas in particular need of interventions to lower their rates.
Health Outcome: Overweight and Obese
Figure 2.1 - Percentage of Adults Obese and OverweightFigure 2.2 - Percentage of Adults Over 60 Years of Age Obese and OverweightFigure 2.3 - Percentage of Children Obese and Overweight
Obesity can be described as a medical condition in which a person has a Body Mass Index (BMI) greater than 30, overweight is defined as a person with a BMI between 25 and 30. DVRPC has included overweight individuals in the measurement of this health indicator due to the high risk of many of these individuals becoming obese, as demonstrated by national trends.
- According to data obtained from the 2009-2010 National Health and Nutrition Examination Survey, over one-third (35.7%) of U.S. adults are obese.
- Pennsylvania's obesity rate in 2010 was 30.5% of citizens.
- Results from the PHMC survey showed that 27% of adults in the DVRPC southeastern Pennsylvania region are obese.
As with national statistics, most of Southeastern Pennsylvania, including Philadelphia, reports high rates of overweight/obesity among the adult population. Only Northeast Chester County, Southeast Montgomery County, and Center City Philadelphia report obesity rates at or below 50%. Center City reports the lowest overweight/obesity rate, with 44% of survey respondents having a high BMI. The Olney/Oak Lane area of Philadelphia reports the highest rate of overweight/obesity with 78% of respondents falling into those categories. See Figure 2.1. [0.2 MB pdf]
The incidence of overweight and obesity can increase throughout one's lifetime. According to PHMC data, 63.4% of older adults in the region are overweight or obese. Center City Philadelphia reports the lowest percentage (36%) of older adults classified as overweight or obese. Olney/Oak Lane in Philadelphia reports the highest percentage (82%) of older adults classified as overweight or obese. See Figure 2.2. [0.2 MB pdf]
As much covered in academic studies and popular media, the obesity rate among children is also rising. However, it is important to note that there is recent evidence that targeted health interventions may be making measurable strides in reducing childhood obesity. In a September 2012 issue brief, the Robert Wood Johnson Foundation (RWJF) noted that among Philadelphia, New York City, Mississippi and California, only Philadelphia reported progress, through its multi-pronged intervention strategy, in reducing childhood obesity. Philadelphia's childhood obesity rate among schoolchildren declined by 4.7% between the 2006-07 and 2009-10 school years. RWJF reports that "the city achieved the most significant declines in obesity rates among African-American males and Hispanic females, two groups at high risk for obesity."
According to 2010 PHMC data, the lowest rates of overweight and obesity are in suburban areas. South Chester County, Central East Chester County, Central East Delaware County, and East Montgomery County all report percentages lower than 22%. Bucolic South Chester County reports the lowest rate (19.6%) of children with high BMIs. Upper North, Lower North, and Bridgesburg/Kensington/Richmond in Philadelphia report the highest percentages of children with high BMIs, with Upper North reporting the highest at 62.5%. See Figure 2.3. [0.2 MB pdf]
Health Outcome: Asthma
Figure 3.1 - Percentage of Adults with AsthmaFigure 3.2 - Percentage of Adults Over 60 Years of Age with AsthmaFigure 3.3 - Percentage of Children with Asthma
Asthma is an acute or chronic inflammatory disease of the airways that can cause shortness of breath, wheezing, or coughing.
- The Centers for Disease Control and Prevention (CDC) report that in 2008, 892,650 adults in Pennsylvania had asthma and the adult lifetime prevalence rate of asthma was 13.3%, which compared precisely with the U.S. rate of 13.3%.
- Results from the PHMC survey suggest that 14.7% of adults surveyed answered that they had been diagnosed as having asthma by a physician.
- However, this question can be misleading as many people who do not have a history of asthma may have been diagnosed with asthma at some point in their lives, such as when battling a chest infection. And other people who do not have health insurance or regularly seek healthcare may suffer from asthma on a regular basis, but have not been diagnosed.
West Montgomery County reports the lowest percentage (8.5%) of adults diagnosed with asthma. Central-East Chester County and Central Bucks County also report fewer than 10% of the adult population diagnosed with asthma. Upper North in Philadelphia reports over 23% of adults diagnosed with asthma. Lower North Philadelphia and South Bucks County also report high rates, with 19.6% and 18.6%, respectively. See Figure 3.1. [0.2 MB pdf]
A lower percentage of older adults surveyed by PHMC report being diagnosed with asthma. Center City Philadelphia and North Montgomery County report fewer than 5% of the older adult population has received an asthma diagnoses. Upper North, Lower North, and Bridesburg/Kensington/Richmond all in Philadelphia report high rates of older adults diagnosed with asthma. See Figure 3.2. [0.2 MB pdf]
The likelihood of children diagnosed with asthma was higher than the adult population. Out of the 2,736 children that were surveyed, 523 (19%) were diagnosed with asthma. It is important to understand the risk that is associated with sensitive groups such as children, due to their increased risk for more asthma related symptoms. The environmental triggers that are associated with the onset of acute asthma include: mold, tobacco smoke (secondhand), outdoor air pollution, and infections linked to influenza, colds, and other viruses. Pennsylvania have been diagnosed with asthma. Center City Philadelphia reports nearly 42% of children diagnosed with asthma. Upper North Philadelphia and North Montgomery County also report high percentages, 30% and 29% respectively. These high rates may be related to regular or high access to healthcare, and consequent diagnosis. Other hypothetical reasons include that some of these children are highly exposed to air pollutants from mobile emissions as they live in areas reporting high congestion and/or high travel demand, such as Center City Philadelphia. See Figure 3.3. [0.2 MB pdf]
Health Outcome: Diabetes
Figure 4.1 - Percentage of Adults with DiabetesFigure 4.2 - Percentage of Adults Over 60 Years of Age with Diabetes
Diabetes is a metabolic disease arising from a person having high blood sugar due to the body's inability to produce enough insulin or when cells are non-responsive to the insulin produced within the body. There are two main types of diabetes which include: type 1, the body's inability to produce insulin; and type 2, the failure of the body to use the insulin produced. Because type 2 diabetes is related to diet and behavior, and possibly access to resources, DVRPC only looked at the prevalence of type 2 diabetes (often referred to as adult onset diabetes), not type 1 (often referred to as childhood diabetes). Previous research has shown that diabetes prevalence increases with age.
- Nationally diabetes affects 25.8 million people (8.3%) of the U.S. population. According to the CDC, [pdf] approximately 18.8 million people are diagnosed with diabetes while 7 million are undiagnosed.
- In 2008, the crude percentage for all adults in Pennsylvania with diabetes was 9.7%.
- It appears that proportionally more adults are diagnosed with type 2 diabetes in Southeastern Pennsylvania than in the U.S. or in the Commonwealth. For all adults surveyed for the PHMC study, 12.7% were diagnosed with diabetes.
- Out of the 3,209 adults over the age of 60 that were surveyed, 686 (21.4%) were diagnosed with diabetes.
Center City Philadelphia, Southeast Montgomery County, and Central Bucks County report the lowest rates of adults with diabetes. Upper North Philadelphia, Olney/Oak Lane Philadelphia and West Philadelphia report the highest rates. See Figure 4.1. [0.2 MB pdf]
The percentage of adults over 60 diagnosed with diabetes is almost double the percentage reported in the total adult population. The geographic distribution is very similar for older adults: Southeast Montgomery County, Center City Philadelphia, and Central Bucks all report the lowest percentages. Upper North Philadelphia and Olney/Oak Lane Philadelphia also report the highest percentages, joined by West Montgomery County. See Figure 4.2. [0.2 MB pdf]
Health Outcome: High Blood Pressure
Figure 5.1 - Percentage of Adults with High Blood PressureFigure 5.2 - Percentage of Adults Over 60 Years of Age with High Blood Pressure
Having high blood pressure can put one at greater risk for heart attacks and strokes. Blood pressure is the force of blood against artery walls as it circulates through the body. High blood pressure is often called the "silent killer" because many do not realize they have it and it often has no warning signs or symptoms. In many cases, high blood pressure is preventable. A healthy diet, physical activity, not smoking, and moderate alcohol use can all support normal blood pressure.
- According to the CDC's Behavioral Risk Factor Surveillance System (BRFSS), 28.7% of Americans have "been told by a doctor or other health professional that" they have high blood pressure or hypertension. The CDC estimates that about 1 in 3 adults with high blood pressure have not been diagnosed.
- In the Southeastern Pennsylvania region, PHMC reports that 35.3% of adults were told by a doctor that they have high blood pressure.
- Please note that neither the national nor regional statistic indicates how many people are currently being treated for and managing high blood pressure.
Center City Philadelphia, Southeast Montgomery County, and Central-East Chester County all report the lowest percentages of adults with high blood pressure, far below the regional average. West, Upper North, and Olney/Oak Lane all in Philadelphia report the highest percentages. In West and Upper North Philadelphia, over 50% of the adult population has been diagnosed with high blood pressure. See Figure 5.1. [0.2 MB pdf]
As with many health issues, one's chance of developing or being diagnosed with high blood pressure or hyper tension increases with age. According to PHMC's survey, over 56% of older adults have been diagnosed with high blood pressure. Center City Philadelphia has the lowest percentage of older adults diagnosed with 36%, followed by North Bucks and Central-South Bucks County. As with the total adult population, Upper North, Olney/Oak Lane, and West Philadelphia all report high percentages of older adults with high blood pressure. See Figure 5.2. [0.2 MB pdf]
Health Disparity Index
Figure 6.1 - Health Disparity Index (Adult Population)
DVRPC created a "healthy disparity index" to visualize the accrual of negative health outcomes in a particular geography relative to the region. A higher numerical score indicates that a higher percentage of adults report having one or more these conditions. This index is incorporated into DVRPC's Community Investment Index.
Health Disparity Index depicts the relative degree to which adults in each planning area report adverse health diagnosis for overweight/obesity, diabetes, asthma, and high blood pressure. The darker colors indicate higher percentages of adults reporting having these conditions, while the lighter colors indicate lower percentages of adults reporting having these conditions. The map shows the most adverse health diagnoses in Upper North, Olney/Oak Lane, West, and Southwest Philadelphia Planning Analysis Sections. The healthiest planning areas (measured by the four conditions) are Bucks Central, Montgomery Southeast, Chester Central-East, Delaware North and Philadelphia Center City.
This map suggests that better health has a direct positive correlation with higher education and income, but development patterns and transportation choices are not to be ignored when addressing the disparities.
Acknowledgements
- Mack Frost, Environmental Specialist, U.S. Department of Transportation, undertook the majority of the research for this Data Snapshot while he was a FHWA Fellow at DVRPC in February and March 2012.
- Nicole Dreisbach, MPH, formerly a Research Associate, and Gary Klein, Senior Data Analyst at the Public Health Management Corporation reviewed the analysis and provided early feedback.
- Ella Carney, Maya Guiterrez, and Saher Hasnain completed a student paper entitled Integrating Health in Long-Range Planning: Recommendations for the Delaware Valley Regional Planning Commission as coursework for a graduate-level course at the University of Pennsylvania on "Community Development and Public Health" (CPLN 622, Prof. Amy Hillier).