Last month in Portland, Ore., Carl and Raylene Worthington's toddler Ava got sick with a blood infection and pneumonia. Both conditions were treatable with antibiotics, but unfortunately for little Ava, her parents belong to the Followers of Christ Church, some members of which believe that prayer can cure the sick. Instead of taking their gravely ill child to a doctor or hospital, they chose to pray for Ava's recovery as she struggled to breathe. The fifteen-month-old died at home on March 2; her parents have been charged with manslaughter.

On March 23 in Wisconsin, eleven-year-old Madeline Neumann died from treatable diabetes. For weeks, Madeline had been obviously and seriously sick, weak from nausea and vomiting. Her parents refused to take their daughter to a doctor, believing instead that God would cure her through prayer. Even after Madeline drew her last breath, her parents prayed over her lifeless body, expecting that their daughter would come back to life.

These are not the first cases of children dying because their parents chose prayer over medicine, and tragically, they won't be the last. Religious faith can be wonderful and inspiring, but is no substitute for proven medicine. While the parents of Ava Worthington and Madeline Neumann did not want their children to die, the issue is not one of malice but neglect.

The parents often try to frame the issue as one of freedom of religion, though that strategy has met with little success. The First Amendment to the U.S. Constitution guarantees freedom of religion, though that freedom does not supercede laws prohibiting child abuse and neglect. Refusing medical treatment in favor of prayer — a remedy with no evidence of success — is certainly neglect.

Many people may be surprised to find that intercessory prayer (petitioning a higher power to heal someone else) has been tested. Several studies have been done to see if people who are prayed for recover any faster (or are cured of disease at a higher rate) than those who are not prayed for.

In 2006, researchers at six major medical centers, including Harvard and the Mayo Clinic, completed the largest study to date. The research ("Study of the Therapeutic Effects of intercessory Prayer 'STEP' in cardiac bypass patients," published in the American Heart Journal) was conducted over nearly a decade and led by Dr. Herbert Benson. It included almost 2,000 cardiac surgery patients who were randomly assigned to one of three groups. One group was prayed for after being told they may or may not be prayed for; the second group was not prayed for after being told the same thing; and the third was prayed for after being told they definitely would be prayed for.

The results: the group that was prayed for did no better than the group that wasn't prayed for. Prayer had no beneficial effect on recovery time, death rate, or other factors. (In fact, if anything, the results suggested that prayer may be harmful: The third group of patients actually fared slightly worse than the other two groups.)

There is no reason to believe that prayer can cure the sick; for that, we must stick with science and medicine. As the cases of Ava Worthington and Madeline Neumann show, it truly is a matter of life and death.

Benjamin Radford is managing editor of the Skeptical Inquirer science magazine. He wrote about the media and pop culture in his book "Media Mythmakers: How Journalists, Activists, and Advertisers Mislead Us." This and other books can be found on his website.