Characteristics associated with ability to prevent adverse drug reactions in hospitalized patients.

We conducted a retrospective analysis to identify characteristics of preventable adverse drug reactions (ADRs). We reviewed reports on 612 ADRs occurring in hospitalized patients over 4 years, identified by the hospital's spontaneous ADR reporting program, and classified the events as potentially preventable or not preventable. Characteristics related to ADR preventability in the univariate analysis were the patient's clinical service, organ system involved in the ADR, class of drug causing the ADR, relationship to dosage, type of ADR, and probability that the reaction was due to the drug. Among these, relationship to dosage (p<0.001) and type of ADR (p<0.001) appeared to be most strongly related to preventability. In a multivariate analysis, preventable ADRs were associated with dosing (OR 3.82, 95% CI 2.42-6.03) and previous allergy to the drug (OR 3.46, 95% CI 1.01-11.88). An ADR that was classified as an allergic (OR 0.50, 95% CI 0.27-0.94) or idiosyncratic reaction (OR 0.44, 95% CI 0.28-0.71) was unlikely to be considered preventable. Preventable ADRs in hospitalized patients are likely to be dosage related or to occur among patients allergic to the specific agent.