Hospital admission rates are often shown and interpreted without
consideration of their inherent variability, which may lead to
faulty conclusions. This may be because theoretically correct
variance estimates are not known for the type of estimates
usually used; i.e., total admissions divided by total person-
months of observation. Here, correct methods for testing and
estimation are shown for situations where they exist. For other
types of data, approximate procedures are proposed and their
properties examined theoretically and empirically, yielding
recommendations for exact and approximate estimation and testing
methods for admission rates in common situations.    Included in
Biostatistics Commons