LONDON (Reuters) - Less than three-quarters of close contacts of positive COVID-19 cases identified by England's test and trace system were reached in the latest weekly figures, Britain's health ...

Background: The proportion of adolescents who return for HIV test results varies widely, and knowledge of what characteristics affect their return is limited. Goal: To quantify the proportion of ...

PHOENIX - According to experts, the percent positive rate for COVID-19 can be the best way to identify community spread, but as it turns out, not all organizations, including the Arizona Department of ...

The NHS Test and Trace system has reached the lowest ever proportion of contacts of people who tested positive for Covid-19 in England. Four in 10 close contacts of people who tested positive are ...

This web calculator conducts a z-test for the difference between two populations' proportions. The calculator includes an explanation of inputs and outputs. This web calculator conducts a z-test for ...

The likelihood ratio test is presented as a natural method to test for the presence of "always buy" and "never buy" consumers. The purchase sequence lengths and sample sizes required to estimate the ...