Competing commitments in clinical trials.

Scholars of the ethics of clinical trials have long recognized a tension between the therapeu tic obligations1 of clinicians (physi cian, nurses, and other health pro fessionals) and the scientific demands of clinical trials.2 The basis for this concern is clear: clini cal care is focused on improving the condition of the presenting patient, while clinical research seeks valid, generalizable informa tion to help future patients. Although in principle both the investigational and control arms of clinical trials are designed to have an equal likelihood of efficacy for the typical patient, in many situa tions research and clinical goals may nonetheless be in conflict. For example, during the recruitment process for a clinical trial, clini cians may have to decide whether to offer participation to a patient who might benefit from the study intervention, but who does not meet the trial's eligibility require ments.3 And once a patient enrolls in a trial, clinicians have to decide whether to deviate from protocol requirements (e.g., dosage of study medication, use of adjunctive med ications, or procedures to collect required study data) for the pur pose of promoting the patient-sub ject's best medical interests. Finally,