Descriptive epidemiology of agranulocytosis
B. L. Strom, J. L. Carson, R. Schinnar, E. S. Snyder and M. Shaw
Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104-6095.
BACKGROUND--To determine the incidence of agranulocytosis, a descriptive
epidemiologic study was performed. METHODS--With the use of computerized
Medicaid billing data from 1980 through 1985 from Minnesota, Michigan, and
Florida, the ratio of persons hospitalized with a discharge diagnosis of
neutropenia to persons with any claim for medical service was first used as
an estimate of the incidence rate of the condition. Patients with cancer
and patients receiving cytotoxic and immunosuppressive drugs were excluded.
The information provided by a review of medical records for a subset of
neutropenia cases was used to determine the proportion with neutropenia
after excluding cases with recurrent or chronic neutropenia, and to
determine the proportion with agranulocytosis. RESULTS--The incidence rates
(95% confidence intervals) of agranulocytosis, excluding recurrent or
chronic disease, were 2.3 (1.4 to 3.7), 7.7 (6.6 to 8.9), and 15.4 (11.3 to
20.4) per million per year in each state, respectively. The overall
incidence was 7.2 (6.3 to 8.1) per million per year.
CONCLUSIONS--Agranulocytosis is an extremely uncommon condition. The excess
risk of agranulocytosis due to any drug other than cytotoxic drugs must,
therefore, be very low.
