Brief communication: Better ways to question patients about adverse medical events: a randomized, controlled trial.

BACKGROUND

There is no standard method of identifying adverse events in clinical trials.

OBJECTIVE

To determine whether 3 different methods of questioning patients about adverse events in a clinical trial affect the frequency of reported events.

DESIGN

Randomized, single-blind, controlled trial.

SETTING

A Veterans Administration medical center, San Francisco, California.

PARTICIPANTS

Men 50 years of age or older who had benign prostatic hyperplasia.

MEASUREMENT

Frequency of self-reported medical problems.

INTERVENTION

The authors randomly assigned 214 men who were undergoing a 1-month, single-blind, placebo run-in period during an existing clinical trial to 3 groups to test different self-administered methods of assessing medical problems at the end of the run-in period. The first group was asked an open-ended question; the second group was asked an open-ended, defined question; and the third group was given a checklist of 53 common side effects.

RESULTS

All 214 patients completed the study. Patients assigned to the checklist group reported a total of 238 adverse events; in comparison, patients who were asked an open-ended question or an open-ended, defined question reported 11 and 14 adverse events, respectively (P < 0.001). The percentage of patients reporting any adverse event was also much higher in the group assigned to the checklist (77%) than in the first group (14%) or second group (13%) (P < 0.001).

LIMITATIONS

The study included only relatively healthy, well-educated, middle-aged men and assessed only self-reported medical problems after the participants had taken placebo for 1 month. All personnel overseeing the study were aware of the group assignments.

CONCLUSIONS

Different methods of collecting patient data regarding adverse events lead to large differences in the reported rates of adverse events in clinical trials, potentially reducing the validity of comparisons between the side effect profiles of drugs and other interventions.