Measures of Disease Frequency

Summary

Develops measures of disease frequency including counts, proportions, odds, and rates, then incidence in its risk and rate flavors with the worked four-person person-month example showing why rate denominators count time rather than people. Connects prevalence to incidence and duration through the formula illustrated by a kitchen-sink simulator, walks through crude, specific, and standardized mortality, and introduces case-fatality rate. Closes with direct and indirect age standardization, the standardized mortality ratio, Years of Life Lost and Years Lived with Disability composing the DALY framework, plus confidence intervals for counts and rates using Poisson and Wilson methods.