Thousands of people every year volunteer for medical experiments that often help them reach cutting-edge treatments but also can expose them to serious risks. Now a major campaign is intended to better educate people about how to weigh whether a study is worth trying.

The centerpiece of the campaign that began Thursday is a patient brochure — to be distributed by hospitals and other locations where research studies are performed — that lists crucial safety questions that people should ask before enrolling.

The questions include: Why is this experiment being conducted? What are the potential side effects? Could my condition get worse instead of better if I participate? What are my other options? Can I drop out if something happens? Does the researcher stand to make money from the work?

"Potential volunteers deserve clear answers before becoming involved," said Jessica Briefer French of the Partnership for Human Research Protection (search). The group, co-founded by the nation's leading hospital watchdog, is conducting the new campaign.

They are questions that Paul Gelsinger, whose 18-year-old son, Jesse, died in 1999 during a gene-therapy experiment, said he wishes he had known to ask.

"People need to know exactly what they are signing up for," said Gelsinger, who applauded the campaign. "I didn't know about the serious dangers Jesse faced until after he died."

Research studies, also called clinical trials, are crucial to the development of new therapies and better understanding of how to use old ones.

Participation may benefit someone, but there are no guarantees. Many experimental treatments fail to work and occasionally even kill participants.

Deciding whether to volunteer is a balancing act that involves wading through scientific jargon, often at a time when a sick patient is desperate for a new approach.

Federal rules require informed consent — signing a document that outlines what will happen during the experiment and the known risks. But just how explicit that informed consent process is varies widely. This problem was highlighted by Jesse Gelsinger's death in an experiment where some federal safety rules were broken and one researcher was found to have financial ties to a company that could have profited from the work.

Several patient-safety organizations offer programs to educate potential research volunteers about the complicated world of medical experiments.

This newest campaign promises to be far-reaching because the brochure will be available through nearly 5,000 hospitals accredited by the Joint Commission on Accreditation of Healthcare Organizations, which co-founded the Partnership for Human Research Protection.

The brochure also is available on the Internet — and from research sites that undergo additional accreditation from the partnership to certify they follow certain clinical trial standards.