About this Site
How to Use this Site
LiveStats: Healthcare Coverage is designed to provide highly localized data about health insurance coverage. For any data topic on this site, use the search bar to select any state, county, or city in the United States. You'll then see local data for the location you've chosen.
When available, local data will include benchmarks against state and national data. On bar charts, benchmarks will display as differently-colored bars. On donut (percentage) charts, you can hover over the black line to see a benchmark value for a parent location.
About the Data
The main data source for this site is the American Community Survey (ACS), conducted by the United States Census Bureau. Unlike the decennial census—an actual count of people in households in the United States every ten years—ACS data is released every year. The data is composed of estimates based on representative surveys.
Data Availability: 1-Year and 5-Year Estimates
Annual data estimates are available from the ACS. But for small populations, these year-by-year estimates are not very accurate. For this reason, this site typically uses 5-year estimate data. The 5-year estimates essentially widen the time period of the survey to 60 months, rather than 12 months. While not as up-to-date, 5-year estimates can show more granular data—like breakdowns of the foreign-born population—with better accuracy. (For locations with under 60,000 people, the ACS only releases data as 5-year estimates.)
Even with 5-year estimates, data may not be available—or reliable—for every location, particularly for very small counties, towns, and villages. We chose not to report extremely unreliable values where the margin of error is larger than the value itself (see below).
Margin of Error
Most charts on this site display a margin of error. Because the ACS provides only estimates, all data on this site has a measure of uncertainty. The margin of error is a +/- range around each estimated value, and essentially shows how uncertain we should be about that value. The margin of error will generally be larger for places with small populations, since these places have a more limited sample size.
Margins of error have an associated confidence level—that is, the degree of confidence that the value actually falls within the error's range. The ACS reports margins of error at a 90% confidence level. However, LiveStories normalizes all margins of error to a 68% confidence level (or one standard deviation). For this reason, the margins of error ranges you see on this site will be smaller than those reported by the ACS, and reflect a greater degree of inherent uncertainty.
With the exception of its subject and data profile tables, the ACS does not report percentage values directly. To better enable comparisons between locations of different sizes, LiveStories calculated percentage values for many topics on this site. Such calculated values are noted, along with their source table, in the "About the Data" section on each page where they occur. LiveStories also calculated the margins of error for the percentage values based on the Census Bureau's guidelines.