Nearly half of older adults have care needs, according to a recent study.

Researchers from the University of Michigan and the Urban Institute found that nearly 18 million older people have difficulty or get help with daily activities.

For the study, researchers collected data from more than 8,000 people included in the 2011 the National Health and Aging Trends Study.

"Although 51 percent reported having no difficulty in the previous month, 29 percent reported receiving help with taking care of themselves or their households or getting around," Vicki Freedman, researcher and co-author of the report, said in a statement. "And another 20 percent said they had difficulty carrying out these activities on their own."

Among those receiving help, one in four lived in either a supportive care setting (15 percent) or a nursing home (10 percent).

Severe disability is more common among those with low incomes, the researchers found. A disproportionate share of low-income persons received assistance with three or more self-care or mobility activities in settings other than nursing homes.

Nearly all older adults had at least one potential informal care network member -- family or household member, or close friend -- and the average network size was four people.

Researchers also found that older adults who lived in the community reported receiving an average of 164 hours of care a month from informal caregivers -- more than five hours a day, on average. Older adults living in supportive care settings reported nearly 50 hours of informal care per month.

About 70 percent of those getting help received assistance from family, friends, and other unpaid caregivers, while about 30 percent received paid care.

However, unmet needs, especially among those receiving paid assistance, were sizable.

"Among the 18 million who had difficulty or received help, 30 percent had an adverse consequence in the last month related to unmet need," Brenda Spillman, co-author of the report, said in a statement. "Among community residents with a paid caregiver, the figure was nearly 60 percent."

Researchers conclude that policies to improve long-term care services and supports, and reduce unmet needs could benefit both older adults and those who care for them.

The findings were recently published in the journal Milbank Memorial Quarterly.