5.9: Where Can We Find Current Public Health Statistics?
Where do the statistics presented by news media and health educators come from? Besides targeted research conducted by the National Institutes of Health (NIH) or universities, there are also a lot of freely available data sources for public health practitioners contained in national, state, and county records. The primary source of national public health information and data is the Centers for Disease Control and Prevention (CDC), an agency of the U.S. Department of Health and Human Services (HHS). Local public health departments may also provide reports to the public on outbreaks and health concerns, research, programs, and health services.
Vital statistics are public records like birth certificates, death certificates and marriage licenses or divorce filings. These get reported to the county clerk and are often a baseline source of data to determine population health status. Each of the 50 states, plus 2 individual cities (New York and District of Columbia) along with the 5 U.S. territories (Puerto Rico, the Virgin Islands, Guam, American Samoa, and the Commonwealth of the Northern Mariana Islands) are responsible for collecting and maintaining these records. The National Center for Health Statistics (NCHS), which is a part of the CDC, tracks these vital records from each state/territory and produces statistics and reports housed in the National Vital Statistics System (NVSS). Data, graphs and charts, and more detailed reports are available to the public online. For example, we can find data on death rates and causes of death for the previous year, statistics on birth rates for women of different age groups, and reports on life expectancy by state ( NVSS , 2023).
Certain diseases are classified as notifiable diseases , requiring doctors, labs, and healthcare workers to report them to health officials. This system of disease surveillance is used to track epidemics and can be a source of data for epidemiologists to use in determining attack rates (more on epidemiology in the next chapter). The list of notifiable disease changes as novel diseases are discovered and older diseases are managed or eradicated. Some diseases or conditions require immediate investigation and response (like foodborne disease outbreaks) and others can be reported on an annual basis (like cancers). This data is collected and managed by the National Notifiable Diseases Surveillance System (NNDSS), another division of the CDC (Seabert et al., 2021, p. 66). As a way to determine its priorities for health investigations and research, the CDC publishes a weekly report called the Morbidity and Mortality Weekly Report (MMWR). You can find these reports published online at www.cdc.gov/mmwr .
The NCHS is also the hub for several national health surveys.
- The National Health Information Survey (NHIS) has been conducted continuously since 1957 and it provides the largest in-depth cross-sectional analysis of population health. The NHIS consists of an interview-style survey which is updated every 15-20 years, and is administered to randomly sampled households in all 50 states. Individuals not included in these samples are those incarcerated, those residing in long-term care or nursing homes, and those without housing ( NHIS , 2022).
- In the early 1960s the National Health and Nutrition Examination Survey (NHANES) began as a project of the NCHS and has continued ever since. This survey includes an interview as well as medical, dental, and physiological assessments conducted on a nationally representative sample of 5,000 people. The data from this survey can be used by epidemiologists to research different diseases and health risks, as well as dietary habits. This project has also helped to develop specific health measurement standards, such as healthy and hypertensive blood pressure ranges. Results can also inform policies and programs to improve health outcomes.
- For adolescents, the Youth Risk Behavior Surveillance System (YRBSS) tracks specific health behaviors and conditions for students in grades 9-12. Things like sexual activity, mental health, nutrition, physical activity, tobacco use, and social experiences are measured. This survey is conducted both at the national level and the state and local levels as well. As of 2021, surveys have been conducted for over 5 million adolescents. These data help to inform not only epidemiologists but also educators and lawmakers in how to support the health of youth. An example project developed from the YRBSS is the CDC’s What Works in Schools , designed to help reduce risky sexual behaviors and teen pregnancies ( Youth Risk Behavior Surveillance System (YRBSS) , 2023).
Local reports, disease surveillance, vital statistics, and national surveys comprise a basis of data from which epidemiological work can be done. In the next chapter, we will discuss epidemiology - i.e. the study of epidemics - and how epidemiologists work to discover trends, causes, risks and protective factors for different types of health issues.