Hospitalizations for aplastic anemia and agranulocytosis in Saskatchewan: incidence and associations with antecedent prescription drug use.

A population-based study to estimate the incidence of hospitalizations for aplastic anemia and agranulocytosis and to evaluate associations between these disorders and antecedent prescription drug use was performed using the Saskatchewan administrative health care databases. Hospital charts and cancer registration data were utilized to apply strict diagnostic criteria to case identification. Estimates of the annual incidence of aplastic anemia and agranulocytosis were 2.7 and 3.0 per million, which are similar to those from other recent population-based studies with comparable case identification criteria. Only a small number of cases were available to evaluate potential drug causes, leading to an analysis of limited power. Nevertheless, significant associations were found between aplastic anemia and tocainide, gold salts, and antidepressants; and between agranulocytosis and anti-thyroids, trimethoprim-sulfamethoxazole, beta-lactams, sulfasalazine, chlorpromazine, carbamazepine, glyburide, and procainamide, although the associations with antibiotics may indicate a response to the disorders rather than a possible cause. These findings are generally consistent with the results of other case-control investigations.