Frequently Asked Questions

• What is the March of Dimes Perinatal Data Center?

• How do I source the data on PeriStats?

• How are the health indicators on PeriStats calculated?

• Is it possible to suggest additional maternal and infant health data sets that could augment the data available on PeriStats?

• Why is data on PeriStats sometimes different from my health department's data?

• Why are data for only certain cities and counties provided on PeriStats?

• For indicators that stratify by race and race/ethnicity how are race and ethnicity determined?

• What are Healthy People 2020 Objectives, and why don't all health indicators on PeriStats cite an objective?

• Why do some printed Web pages look different than the page viewed on a computer screen?

• What is the 'd link' in the bottom right corner of every graph?

• What should I do if pop-up blocker blocked my web page

• What are the HHS Regions?

• What are Confidence Intervals?

Q.

What are Confidence Intervals?

A.

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 reported 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.