Frequently Asked Questions

1. What is the March of Dimes Perinatal Data Center?

   The Perinatal Data Center is located at the March of Dimes National Office in Arlington, VA. The Perinatal Data Center's role is to acquire and analyze maternal and infant health data, and to interpret this information for the March of Dimes and for health professionals, research groups and organizations external to the March of Dimes.

   Prematurity is one of the leading casues of infant death in the United States. The mission of March of Dimes is to change that and help more moms have full-term pregnancies and healthy babies. From polio to prematurity the March of Dimes has focused on researching the problems that threaten our children and finding ways to prevent them. The goal of the Perinatal Data Center is to clearly present perinatal data, so that professionals focused on issues related to maternal and infant health can make more informed decisions to ultimately improve infant health. To fulfill this objective, the Perinatal Data Center staff collaborate and provide guidance on epidemiologic and statistical analyses and grants, and present analytical findings at national conferences and in peer-reviewed journals.

   To contact the March of Dimes Perinatal Data Center, e-mail us at [email protected].

2. How do I source the data on PeriStats?

   The data on PeriStats originates from multiple agencies. Sources and a suggested citation are listed below the graph, map or table for each data point. In addition to the source agency, a citation should include the PeriStats website address and the date it was retrieved.

   Sample Citation:

   National Center for Health Statistics, final natality data. Retrieved October 6, 2017, from www.marchofdimes.org/peristats.

3. How are the health indicators on PeriStats calculated?
   The majority of the health indicators on PeriStats are calculated by the March of Dimes Perinatal Data Center using data obtained electronically from the source agency. Those data not calculated directly by the Perinatal Data Center are obtained directly from the source agency or their publications. Please see the Calculations section located on the ‘About Us’ page of the website for a more detailed description of the methods used to calculate data on PeriStats.
4. Why is data on PeriStats sometimes different from my health department's data?

   Data provided on PeriStats may differ from rates obtained by state health departments and vital statistics agenceis for multiple reasons. As part of the Vital Statistics Cooperative Program, states are required to send the National Center for Health Statistics (NCHS) natality and mortality data for a given year by a specific date. Sometimes states receive data after this date, which may result in slight differences in the rates calculated using NCHS-processed data and state processed data. Another reason rates may vary could be due to differences in the way NCHS and the states calculate variables and impute missing data. Please see the Calculations section for a more detailed description of the methods used to calculate specific health indicators on PeriStats.

   While one strength of PeriStats is the ability to make comparisons between states/local areas or between any state/local area and the U.S., PeriStats is only a starting point for obtaining state and local data. We encourage users to work with their state health departments to analyze data in order to gain a deeper understanding of maternal and infant health issues specific to their area.

5. Why are data for only certain cities and counties provided on PeriStats?
   In an effort to provide more information by geographic area, detailed data for certain cities and counties are provided on PeriStats. Specific criteria, including a minimum number of live births in a given year, were used to ensure that there were adequate counts of events to calculate a majority of the rates and percentages using National Center for Health Statistics data. Data from other sources used in PeriStats are not generally available at the city and county level.
6. For indicators that stratify by race and race/ethnicity how are race and ethnicity determined?
   Data provided by race and race/ethnicity reflect the race and ethnicity of the mother as indicated on the birth certificate. Race categories shown on PeriStats include: White, Black, American Indian/Alaska Native, and Asian/Pacific Islander, consistent with those reported by the National Center for Health Statistics (NCHS). Race/ethnicity categories include: non-Hispanic White, non-Hispanic Black, non-Hispanic American Indian/Alaska Native, non-Hispanic Asian/Pacific Islander, and Hispanic. Race and ethnicity are reported separately on the birth certificate. When race of the mother is missing from the birth certificate, NCHS imputes race using race of the father, if available, or by assigning the specific race of the mother on the preceding record with a known race of mother (6.8% of live births in 2019).
7. What are Healthy People 2030 Objectives, and why don't all health indicators on PeriStats cite an objective?
   Healthy People 2030 (HP2030) is a set of health objectives for the United States to achieve over the third decade of the new century. Created by scientists both inside and outside of government, it identifies a wide range of public health priorities and specific, measurable objectives. HP2030 is used by many different people, states, communities, professional organizations, and others to help develop programs to improve health. When available, PeriStats provides the relevant maternal or infant health HP2030 objective. Go to the HP2030 website for more detailed information.
8. What are the HHS Regions?

   The U.S. Department of Health and Human Services (HHS) divides the country into 10 regions with a regional office located within each one. Some data points are available by HHS region. They are:

   • Region 1-Boston: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont.
   • Region 2-New York: New Jersey, New York, and the territories Puerto Rico and the Virgin Islands. (Data for territories are not included in calculations on PeriStats.)
   • Region 3-Philadephia: Delaware, District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia.
   • Region 4-Atlanta: Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee.
   • Region 5-Chicago: Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin.
   • Region 6-Dallas: Arkansas, Louisiana, New Mexico, Oklahoma, and Texas.
   • Region 7-Kansas City: Iowa, Kansas, Missouri, and Nebraska.
   • Region 8-Denver: Colorado, Montana, North Dakota, South Dakota, Utah, and Wyoming.
   • Region 9-San Francisco: Arizona, California, Hawaii, Nevada and the territories American Samoa, Commonwealth of the Northern Mariana Islands, Federated States of Micronesia, Guam, Marshall Islands, and Republic of Palau. (Data for territories are not included in calculations on PeriStats.)
   • Region 10-Seattle: Alaska, Idaho, Oregon, and Washington.

   For more information on HHS regions and the contact information for each region, see https://www.hhs.gov/about/agencies/iea/regional-offices/index.html .

9. What are Confidence Intervals?
   Data from the Pregnancy Risk Assessment Monitoring System (PRAMS) are based on a sample of women in each state who have had a recent live birth. The rates of selected indicators are estimates of the value for all women who gave birth in that state in that year. The 95% confidence interval around the estimate is the range of values that have a 95% chance of containing the actual percentage for that indicator among all women in that state. When comparing percentages between groups (for example, comparing the percent of women who reported ever breastfeeding by race/ethnicity), differences would only be considered statistically significant if the 95% confidence intervals do not overlap one another.