Such facilities have lower staffing levels and higher rates of serious patient-care violations than small chains and independently owned homes, according to the newspaper’s review.

“Ownership is certainly a factor in quality of care,” Toby Edelman, senior policy attorney with the nonprofit Center for Medicare Advocacy, told the Courant.

He said many of the larger chains have complex organizational structures with multiple layers of management.

“They send a lot of money to their corporate offices,” he said. “There can be a lot of distance between the owners and the facilities themselves. They’re not on the ground.”

The Courant looked at two years of inspection and ownership data from the federal Centers for Medicare and Medicaid Services for the more than 240 licensed nursing homes in Connecticut.

Adjusted for size, homes owned by large chains provided, on average, 16 percent fewer registered and licensed nurses than small-chain and independent nursing facilities, according to the data.

The state’s large-chain homes had a 30 percent higher rate of causing patients harm or putting them in immediate jeopardy, the Courant determined. For the five large chains in Connecticut, which control about one third of the state’s nursing home beds, such serious deficiencies occurred at a 42 percent higher rate than at homes not controlled by large chains.

Toni Fatone, executive vice president of the Connecticut Association of Health Care Facilities, cautioned against looking at the ownership structure of a nursing home and drawing conclusions.

“Inadequate Medicaid funding is going to be the biggest differential in any of these buildings,” she said.

Data from the last two years show about 70 percent of the state’s licensed nursing homes, 169 facilities, were owned by chains. The federal government defines a chain as having two or more homes.

Leeway Inc, a small, independent, nonprofit nursing home in New Haven, had the best staffing levels in the state. There are about 44 registered and licensed nurses for every 100 beds. In contrast, four homes owned by large for-profit chains — in Manchester, Waterbury, Farmington and Shelton — had fewer than seven licensed and registered nurses per 100 beds.