Background: Voluntary physician reporting of adverse drug events (ADEs) in among their patients remains the single most important source of information on serious and rare ADEs. Yet, substantial under-reporting exists and the factors producing its causes are unclear.
Objectives: The objectives of the study are to: (1) identify the practitioner's demographic and professional characteristics associated with ADE reporting; and (2) identify knowledge, attitudes, and opinions associated with ADE reporting.
Design: Case-control study.
Subjects: Physicians within the National Health Service in Galicia (Northwestern Spain). The 194 case doctors are those who reported at least one ADE to the regional drug surveillance center between 1991 and their enrollment in the study. The 498 controls were randomly selected among the remaining physicians. All were interviewed using a mail questionnaire.
Main outcome measures: We used logistic regression to determine the ADE reporting odds ratio.
Results: The response rate was 63.7%. The probability of reporting ADEs increases with increasing volume of prescriptions and decreases with increasing patient load. The following attitudes are associated with a smaller probability of reporting: (1) belief that really serious adverse drug events are well documented by the time a drug is marketed; (2) belief that it is nearly impossible to determine if a drug is responsible for a particular adverse event; (3) only reporting an adverse drug reaction if one is sure that it is related to the use of a particular drug; and (4) belief that the one case an individual physician might see cannot contribute to medical knowledge.
Conclusions: Some physician attitudes regarding ADEs are associated with underreporting.