survey (version 4.4-2)

myco: Association between leprosy and BCG vaccination

Description

These data are in a paper by JNK Rao and colleagues, on score tests for complex survey data. External information (not further specified) suggests the functional form for the Age variable.

Usage

data("myco")

Format

A data frame with 516 observations on the following 6 variables.

Age

Age in years at the midpoint of six age strata

Scar

Presence of a BCG vaccination scar

n

Sampled number of cases (and thus controls) in the age stratum

Ncontrol

Number of non-cases in the population

wt

Sampling weight

leprosy

case status 0/1

Details

The data are a simulated stratified case-control study drawn from a population study conducted in a region of Malawi (Clayton and Hills, 1993, Table 18.1). The goal was to examine whether BCG vaccination against tuberculosis protects against leprosy (the causative agents are both species of _Mycobacterium_). Rao et al have a typographical error: the number of non-cases in the population in the 25-30 age stratum is given as 4981 but 5981 matches both the computational output and the data as given by Clayton and Hills.

Examples

data(myco)
dmyco<-svydesign(id=~1, strata=~interaction(Age,leprosy),weights=~wt,data=myco)

m_full<-svyglm(leprosy~I((Age+7.5)^-2)+Scar, family=quasibinomial, design=dmyco)
m_age<-svyglm(leprosy~I((Age+7.5)^-2), family=quasibinomial, design=dmyco)
anova(m_full,m_age)

## unweighted model does not match
m_full
glm(leprosy~I((Age+7.5)^-2)+Scar, family=binomial, data=myco)