Background It is essential to record incidents in clinical trials (CT) to monitor them appropriately. It is a basic tool to analyse and detect problems.

Purpose To analyse the development in prescription incidents recorded from 2009 to 2011, to identify and resolve quality problems, with the aim of establishing corrective actions to reduce CT problems in a process of continual improvement.

Materials and Methods The most frequent incidents were found in the prescription phase. Data were recorded using the following items: date, person reporting, CT identification, department, professional involved, description of the problem and corrective measures. The evolution of incidents was analysed by chi square.

Results 186 events were recorded in a total of 331 CTs. The most frequent events occurred mainly in the prescription phase (49.0%) followed by dispensing (22.1%), recording (9.6%) and reception (8.6%). The causes of prescribing incidents during 2009, 2010 and 2011 were respectively: no specification that the patient was included in CT (74.2%, 27.1% and 5.3%); incomplete prescription (2.6%, 24.2% and 31.6% ), non-adherence to the study protocol (2.6%, 12.2% and 15.8%), incorrect dose (18%, 18.2% and 36.8%) and other causes (2.6%, 18.2% and 10.5%). The percentage of prescription incidents was: 2.01% (n = 1932) in 2009, 1.64% (n = 2012) in 2010 and 0.92% (n = 2050) in 2011. Prescribing incidents decreased significantly in 2011 compared to previous years. In these cases, there was an immediate intervention with a communication to the investigator.

Conclusions To manage the process as the Ethics Committee requires it is essential to have excellent communication and coordination between the pharmacy department and the other professionals involved. Measures taken were: increased electronic prescribing, using a specific application for CT prescribing and communication to researchers. The measures were effective in achieving a reduction in incidents in CT prescribing.

No conflict of interest.