plotFars: Extract from FARS data set the ratio of ratios estimate
of safety device effectiveness, and return trellis graphics object
Description
Safety devices may be airbags or seatbelts. For airbags, alternatives
are to use airbag installed or airbag deployed as the
criterion. Ratio of driver deaths to passenger deaths are calculated
for driver with device and for driver without device, in both cases for
passenger without device.
Usage
plotFars(restrict =
"age>=16&age
Arguments
restrict
text: an expression that restricts observations considered
fatal
numeric: 4 for fatal injury, or c(3,4) for incxapacitating or
fatal injury
statistics
Vector of character: ratio of ratios variables that wil be plotted
Value
A graphics object is returned
Details
Note that the airbag deployed statistic is not a useful measure
of airbag effectiveness. At its most effective, the airbag will deploy
only when the accident is sufficiently serious that deployment will
reduce the risk of serious injury and/or accident. The with/without
deployment comparison compares, in part, serious accidents with less
serious accidents.