Over three years [after it was purchased by Formation Capital, 15 residents at Habana Health Care Center] died from what their families contend was negligent care... [Investors in nursing homes] include prominent private equity firms like Warburg Pincus and the Carlyle Group... As such investors have acquired nursing homes, they have often reduced costs... But by many regulatory benchmarks, residents at those nursing homes are worse off... Regulators say residents at these homes have suffered...[and] have fared more poorly than occupants of other homes in common problems like depression... [P]rivate investment companies have made it very difficult for plaintiffs to succeed in court and for regulators to levy chainwide fines by creating complex corporate structures that obscure who controls their nursing homes... Investors in these homes say such structures...have helped them revive an industry that was on the brink of widespread bankruptcy... Representatives of all the investment groups that bought nursing home chains since 2000 — Warburg Pincus, Formation, National Senior Care, Fillmore Capital Partners and the Carlyle Group — were offered the data and findings from the Times analysis. All but one declined to comment. An executive with a company owned by Fillmore Capital...said that because some data regarding the company were missing or collected before its acquisition, The Times’s analysis was not a complete portrayal of current conditions... [Habana was operated by affiliates of Warburg Pincus including Tampa Healthcare, Seacrest Healthcare, Florida Health Care Properties (now Epsilon Health Care Properties), Sawgrass Financing, Probatis Health. In response to concerns about health conditions at Habana,] Warburg Pincus and its affiliates declined to discuss the citations. Formation said it was merely a landlord. “Formation Properties owns real estate and leases it to an unaffiliated third party that obtains a license to operate it as a health care facility,” Formation said. “...Formation Properties...has no involvement or control over the operations at the facility or any entity that is involved in such operations.”