ADVERSE DRUG REACTION REPORTING IN A MULTICENTER SURVEILLANCE STUDY

OBJECTIVE: To evaluate the performance of a multicenter, prospective s urveillance program in identifying adverse events, and to seek explana tions for misclassification bias. DESIGN: The design was a prospective observational study of patients with documented or suspected bacteria l pneumonia. SETTING: Data were collected in 74 acute care hospitals a cross the US. PATIENTS: This evaluation was based on a consecutive sam ple of 1822 adult patients (>18 years of age) with documented or suspe cted bacterial pneumonia who were being treated with a cephalosporin, a penicillin, or an aminoglycoside over a 3-month period. Patients wer e followed for the duration of antibiotic therapy and were excluded if antibiotic therapy was <3 days or if the pneumonia was judged to be n onbacterial. INTERVENTIONS: Clinical pharmacists documented patient de mographics, concurrent illnesses and medications, antibiotic administr ation, relevant laboratory data, and the occurrence of nephrotoxicity and neutropenia. MAIN OUTCOME MEASURES: Validity of investigators' ide ntification of neutropenia and nephrotoxicity as compared with objecti ve laboratory data was assessed by using sensitivity, specificity, and positive and negative predictive value measures. RESULTS: Among the 1 502 patients with sufficient data to evaluate neutropenia, there was a greement in 1270 patients (84.6%); likewise, among 1291 patients with sufficient data to evaluate nephrotoxicity there was agreement in 1186 patients (91.9%). Sensitivity of the researchers' assessments was 50. 9% and 71.0% for neutropenia and nephrotoxicity, respectively. The neg ative predictive value was >95% for both events. CONCLUSIONS: Overall, this evaluation demonstrated that the Drug Surveillance Network can s uccessfully identify targeted adverse events. Moreover, this study hig hlights the importance of validation for all types of outcomes-oriente d research studies.