[Significance of age, sex, kidney function, atopy and number of prescriptions for the occurrence of adverse drug reactions, studied by multivariate statistical methods. Results from the Comprehensive Hospital Drug Monitoring Berne (CHDMB)].

UNLABELLED: The influence of five factors (age, sex, renal function, atopy and number of drugs) on the incidence of adverse drug reactions (ADRs) is analysed by multivariate statistical methods (loglinear models for contingency tables). The study is based on a total of 19,653 inpatients in the "Comprehensive Hospital Drug Monitoring Berne (CHDMB)".
RESULTS: 1. The risk of ADRs mainly increases with the number of drugs. 2. Increasing age and female sex are also confirmed as risk factors by these statistical methods. Reduced renal function (increased serum creatinine) is strongly correlated with advancing age. Renal function, however, yields more pertinent information on ADR risk than does age. 3. In atopic and non-atopic patients, the ADR risk is identical. In both groups of patients the same number of drugs was given. If the pathogenetic mechanisms of the ADRs (allergic or pharmacologic in the broad sense) are considered, it is found that atopic patients show a ratio of about 2:1 pharmacologic to allergic reactions, compared to about 3:1 in non-atopic subjects. A reduction in the incidence of ADRs is best attained by even more restricted use of drugs and better and earlier adaptation of drug dosage to diminished renal function.