(AP) A significant number of crib deaths occur in daycare, where caretakers may be less likely to have heard about the importance of putting babies to sleep on their backs, new research suggests.

In a study of 1,916 SIDS cases in 11 states, researchers found that about 20 percent, 391 deaths, occurred in daycare settings.

Sixty percent of the daycare deaths occurred in home daycare, which tend to be unlicensed and run by older women with less access to pediatricians and others who promote SIDS risk reduction efforts, said Dr. Rachel Moon, the lead author. She is a pediatrician at Children's National Medical Center in Washington.

Her data on SIDS deaths from January 1995 to June 1997 appear in the August issue of Pediatrics, published Monday by the American Academy of Pediatrics.

Especially disturbing, Moon said, was the finding that of children placed on their stomachs by caretakers, more than half were usually put to sleep on their backs by their parents.

Previous research has shown that compared with babies who always sleep on their backs, back sleepers switched to their stomachs are 20 times more likely to die of SIDS and habitual stomach sleepers are about five times more likely, Moon said.

Moon and others theorize that habitual back-sleepers are more vulnerable because they don't develop upper body strength as early as stomach sleepers, who have to lift their heads or arms to see what's around them.

SIDS deaths in child-care ranged from a high of 40 percent of all SIDS deaths in Minnesota to a low of 9 percent in Florida, with an average of 20.4 in all 11 states. The other states in the study were Arizona, California, Colorado, Maryland, Massachusetts, Michigan, Missouri, New Hampshire and New Jersey.

Dr. John Kattwinkel, chairman of an American Academy of Pediatrics SIDS task force, called the findings “very worrisome.”

The highest risk period for SIDS is when infants are two months to five months old, which is often the time working mothers return to their jobs after childbirth, Kattwinkel said.

“It's just one other bit of evidence from a national health standpoint that tells us we ought to be educating daycare centers and grandparents ... as well as parents” about back-sleeping, he said.

SIDS deaths have decreased by about 40 percent nationwide since advocates launched the “Back to Sleep” campaign in the early 1990s.

Though its cause is unknown, SIDS resembles suffocation and parents are advised to have babies sleep on their backs to avoid blocking their airways. Soft mattresses, loose bedding, pillows and soft toys also should be kept out of cribs.

Some advocates, like the SIDS Alliance, even go so far as to advise against putting any blankets in cribs and instead say babies should sleep in one-piece “sleepers” in cold weather to stay warm.

SIDS Alliance spokeswoman Phipps Cohe said all child-care providers should be requireto have SIDS risk reduction education.

Census figures indicate about 17 percent of children under 1 year of age are in some kind of child-care setting, Moon said.

Cohe said parents who leave their infants in day care should “be very specific about the way you want your baby positioned to sleep. Parents need to spell it out, put it in writing if necessary.”