Center for Disease Control and Prevention (CDC): Data and Statistics

Healthy People 2020 provides science-based, 10-year national objectives for improving the health of all Americans.

U. S. Census  (2010) it is the National Census after all.   If you cannot find the information you need, check the 2000 U. S. Census. (The census is gathered once every 10 years.)

A great resource to look at is Ebling Library's "Health Statistics Portal".  Many resources have been compiled together and then broken down into separate morbidities, gender, and geographic location.

Please remember the "most current" statistics for the United States may be approximately 2 years old.  This is normal as it takes over a year to analyze the data gathered.

• Incidence and Prevalence
• Likelihood Ratios
• Number Needed to Treat
• Pre-Test Probability
• SpPins and SnNouts

A confidence interval (CI) can be used to show within which interval the population's mean score will probably fall.  Most reseachers use a CI of 95%.  By using a CI of 95%, researchers accept there is a 5% chance they have made the wrong decision in treatment.  Therefore if 0 falls within the agreed CI, it can be concluded that there is no significant difference between the two treatments.  When 0 lies outside the CI, researchers will conclude that there is a statisticallyHalfens significant difference.

Halfens, R. G., & Meijers, J. M. (2013). Back to basics: an introduction to statistics. Journal Of Wound Care, 22(5), 248-251.

Categorical (nominal) tests
This category of tests can be used when the dependent, or outcome, variable is categorical (nominal), such as the dif­ference between two wound treatments and the healing of the wound (healed versus non­healed). One of the most used tests in this category is the chi­squared test (χ2). The chi­squared statistic is calculated by comparing the differences between the observed and the expected frequencies. The expected frequencies are the frequencies that would be found if there was no relationship between the two variables. 

Based on the calculated χ2 statistic, a probability (p ­value) is given, which indicates the probability that the two means are not different from each other. Researchers are often satisfied if the probability is 5% or less, which means that the researchers would conclude that for p < 0.05, there is a significant difference. A p ­value ≥ 0.05 suggests that there is no significant difference between the means.

Halfens, R. G., & Meijers, J. M. (2013). Back to basics: an introduction to statistics. Journal Of Wound Care, 22(5), 248-251.