Survey of investigators' opinions on the acceptability of interactions with patients participating in clinical trials.

INTRODUCTION

There is growing concern about the ability of clinical trials to reliably detect differences between active drugs and placebo. To date, little attention has focused on how interactions between clinical trial investigators and patients may influence study outcomes. We sought to explore what types of interactions with patients investigators considered to be appropriate during placebo-controlled pharmacotherapy studies of major depressive disorder.

METHODS

Questionnaires describing 26 specific types of clinician-patient interactions were administered to principal investigators (PIs) attending an investigators meeting for a phase 3 clinical trial of an antidepressant medication. Principal investigators were asked to rate the acceptability of each intervention. They were also asked to report the mean time they spent with patients at a midstudy visit. Principal investigators were grouped according to previous trial experiences (participation in <20 or > or =20 prior trials).

RESULTS

Principal investigators generally agreed that physical health recommendations and nonspecific interactions with study patients were acceptable. Relating the investigator's personal experiences and siding with the patient on interpersonal conflicts were consistently rated as unacceptable. Less-experienced PIs were significantly more likely to view as acceptable cognitive, behavioral, and emotionally supportive interventions compared with more-experienced PIs. Forty-two percent of PIs reported spending at least 20 minutes with patients at midstudy visits.

CONCLUSIONS

There is significant variability between PIs in what are considered to be appropriate interactions with patients participating in clinical trials. Greater standardization of these interactions is required to reduce placebo response rates and to strengthen the ethical conduct of clinical trials.