Families of children with special needs provide billions of dollars in unpaid medical care each year, researchers say, significantly compromising their own ability to earn a living.

Data collected from more than 40,000 parents or guardians of those with special needs across the country suggests that about half of these kids — some 5.6 million children — need assistance at home with managing everything from feeding to breathing equipment and physical therapy.

“If parents did not provide this care at home, children would need to stay in the hospital longer, professionals would need to come to the home or children might not get the care that their physicians prescribe,” said Mark Schuster, chief of general pediatrics at Boston Children’s Hospital and a senior investigator on the study which was published recently in the journal Pediatrics.

“Parents want to do everything they can for their children, but it can be a real challenge to juggle their ill child, their other children and sometimes their job,” he said.

All told, families provide nearly $36 billion worth of care annually, the study found. On average, kids with special needs received 5.1 hours of medical care from family members each week, but that figure grew to 11.2 hours weekly for those with intellectual disability and 14.4 hours for those with cerebral palsy.

These estimates don’t factor time families spend helping with daily activities like bathing and dressing, researchers said.

The findings come from an analysis of data collected through the 2009-2010 National Survey of Children with Special Health Care Needs.

Families lose out on an estimated $3,200 in earnings per year related to their medical caregiving responsibilities for each child, the study found, or over $17 billion collectively. If they were to hire aides to provide medical care, it would run between $2,100 and $6,400 annually per child, costs that researchers said can be prohibitive for many families.

Beyond the financial toll, those behind that study noted that the added responsibilities of providing medical care for a child can also bring emotional stress.

“We need to do a better job of training family caregivers in how to take care of their children at home, and we need better supports for them,” Schuster said.