[How much information is retained by participants in clinical trials?]

To assess which information participants of the Dutch TIA trial could remember from the informed consent procedure.

Descriptive investigation.

The University Hospital Utrecht and the University Medical Centre Amsterdam.

One hundred of the 308 patients from 2 of the 63 participating clinical centres (the University Hospital Utrecht and the University Medical Centre Amsterdam), were selected at random for telephone interviews. Nineteen were not interviewed, most of them because they did not have access to a telephone. By a weighted score based on the replies the influence of some baseline variables was explored. The information sheet that patients had received was analysed with the readability tests of Flesh and Fry.

Eighty-six percent of all patients were aware of the correct diagnosis. The name and action of the trial drug Ascal (a brand of acetylsalicylic acid) were retained better than those of atenolol. The nature of the disease and therapy were better known than the design of the trial. Of the baseline variables explored only the level of education was significantly related to what patients remembered about the trial. The readability of the information sheet required more education than was intended.

Although we did not study a random sample the conclusion seems warranted that the level of information was not optimal in this trial.