matched {MESS}

Flu hospitalization

Description

Researchers in a Midwestern county tracked flu cases requiring hospitalization in those residents aged 65 and older during a two-month period one winter. They matched each case with 2 controls by sex and age (150 cases, 300 controls). They used medical records to determine whether cases and controls had received a flu vaccine shot and whether they had underlying lung disease. They wanted to know whether flu vaccination prevents hospitalization for flu (severe cases of flu). Underlying lung disease is a potential confounder.

Format

A data frame with 450 observations on the following 4 variables.

id

a numeric vector

iscase

a factor with levels Control Case

vaccine

a factor with levels Not Vaccinated

lung

a factor with levels None Disease

Source

Modified from: Stokes, Davis, Koch (2000). "Categorical Data Analysis Using the SAS System," Chapter 10.

Examples

data(matched)