The consent form as a possible cause of side effects

Area of Science:

• Clinical Medicine
• Pharmacology
• Medical Ethics

Background:

• Unstable angina treatment trials often involve aspirin or sulfinpyrazone.
• Informed consent is crucial for ethical clinical research.
• Understanding factors influencing patient withdrawal is vital for trial integrity.

Purpose of the Study:

• To investigate the impact of mentioning gastrointestinal side effects in informed consent forms on patient withdrawal in unstable angina trials.
• To differentiate between subjective symptom reporting and physician-diagnosed major complications.

Main Methods:

• A multicenter trial comparing aspirin and sulfinpyrazone for unstable angina.
• Two of three centers included specific mention of gastrointestinal side effects in consent forms.
• Comparison of patient withdrawal rates and reasons across centers.

Main Results:

• A sixfold increase in withdrawals due to subjective gastrointestinal symptoms was observed in centers mentioning these side effects (P < 0.001).
• No significant difference in major gastrointestinal complications (peptic ulcer, bleeding) was found between centers.
• Withdrawals were primarily linked to subjective, minor gastrointestinal symptoms, not non-gastrointestinal side effects.

Conclusions:

• Informing patients about potential gastrointestinal side effects in consent forms may lead to increased reporting and withdrawal due to minor symptoms.
• This highlights the potential for consent form content to influence patient perception and behavior during clinical trials.
• Careful wording in informed consent is necessary to balance ethical disclosure with maintaining trial validity.