oddsratio: (Log) Odds Ratios

Description

Computes (log) odds ratios and their asymptotic standard errors for (possibly) stratified data.

Usage

oddsratio(x, stratum = NULL, log = TRUE)
## S3 method for class 'oddsratio':
plot(x, conf_level = 0.95, type = "o",
  xlab = NULL, ylab = NULL, xlim = NULL, ylim = NULL, whiskers = 0.1,
  baseline = TRUE, transpose = FALSE, \dots)

Arguments

a 2 by 2 by ...table.

stratum

vector of strata dimensions.

log

if FALSE, ordinary odds ratios are computed.

conf_level

if not NULL or FALSE, conf_level-% confidence intervals are plotted for each data point.

type

plot type.

xlab

label for the x-axis. Defaults to "Strata" if transpose is FALSE.

ylab

label for the y-axis. Defaults to "Strata" if transpose is TRUE.

xlim

x-axis limits. Ignored if transpose is FALSE.

ylim

y-axis limits. Ignored if transpose is TRUE.

baseline

if TRUE, a red dashed line is plotted at a value of 1 (in case of odds) or 0 (in case of log-odds).

transpose

if TRUE, the plot is transposed.

whiskers

width of the confidence interval whiskers.

...

other graphics parameters (see par).

Value

An object of class "logoddsratio", which is simply a vector of (log) odds ratios with dimensionality depending on stratum, along with the following attributes:
ASEa numeric vector with the asymptotic standard errors.
loglogical indicating whether log odds ratios or common odds ratios are computed.

References

M. Friendly (2000), Visualizing Categorical Data. SAS Institute, Cary, NC.

Examples

Run this code

## load Coal Miners data
data("CoalMiners")

## compute log odds ratios
lor <- oddsratio(CoalMiners)
lor

## summary with z tests
summary(lor)

## confidence intervals
confint(lor)

## visualization
plot(lor,
     xlab = "Age Group",
     main = "Breathelessness and Wheeze in Coal Miners")

## add quadratic model
g <- seq(25, 60, by = 5)
m <- lm(lor ~ g + I(g^2))
lines(fitted(m), col = "red")