[Negative results associated with medication in the emergency department of a hospital]

To find out the prevalence of negative results associated with medication (herein referred to as NRM) in patients attending the emergency department. To classify the results by severity, avoidability and cost, as well as to establish the factors associated with their appearance.

Observational, descriptive and cross-sectional study carried out in the emergency department of a tertiary hospital. Patient surveys and emergency department records were used as sources of information. The Dader Method and guidelines from the Third Consensus of Granada were used. Pearson's chi2 test was used to find the association between age, gender and number of drugs and showing signs of NRM. Avoidability was measured using Baena et al's criteria and severity was assessed according to whether or not the patient had been admitted into an observation stall or on to a hospital ward.

24.4% of patients visited the emergency department because of NRM. 16.1% needed to be hospitalised to solve their health issue. 83.9% of all patients with NRM and 77.3% of those hospitalised due to NRM could have been avoided. Statistically, there was a higher prevalence of NRM in patients taking 5 or more different drugs. An estimated euro 14,666,178 was spent on treating avoidable NRM cases in 2003.

The prevalence of NRM in those who attended the emergency department, the high percentage of avoidability and the cost imposed on the Health Service seem to sufficiently argue a case for the consideration that NRM as a problem which requires the implementation of prevention programmes based on drug-treatment monitoring.