ARLINGTON HEIGHTS, ILL.– Bob Landorf walked miles during his hospital stay, dragging his IV pole along, too, on a mission to upend disturbing statistics for patients his age.

At least one-third of hospital patients older than 70 leave more frail than when they arrived, and many become too weak to go home. Nursing home care or rehabilitation often are needed, and even then, research suggests more than two-thirds remain weaker a year after being in the hospital.

Elder-care experts challenge the idea that this decline is an inevitable part of growing old. They say conventional hospital care focusing on treating disease rather than preventing frailty contributes to the problem.

“Nonmedical people say, ‘Grandma went to the hospital with pneumonia … and she was never the same again,” said Dr. Kenneth Covinsky, a geriatrics specialist at University of California at San Francisco. “Pneumonia is a serious illness, but it is treatable” and should not leave patients disabled.

He and other advocates say hospitals need to revamp old-fashioned models of patient care to address the nation’s aging population — from getting patients out of bed to offering better food and homey surroundings.

“Life has 100 percent mortality. But if you can change the age at which people lose function,” they may live longer, better lives, said Covinsky, who wrote about the issue recently in the Journal of the American Medical Association.

Some already are heeding the call, including the suburban Chicago hospital where Landorf was recently treated.

Intestinal discomfort sent Landorf to Northwest Community Hospital in Arlington Heights last month. Doctors put the 74-year-old part-time chemist on intravenous fluids and ran tests for a suspected blockage. But they didn’t confine him to bed.

Two hospital units have volunteers who accompany patients on daily walking sessions of at least 15 minutes, their course marked by footprint decals on hallway walls. Landorf figures he did at least 20 laps daily during his stay.

His only complaint? “It would be nice if they had longer paths,” he said.

Doctors found no intestinal blockage and sent him home after three days. Now he’s back to working out three times a week, just like before his hospital stay.

Landorf thinks all that walking helped keep him in shape. The benefit is obvious, he said. “Any kind of exercise you can get when you’re bedridden is good.”