Several nurses interviewed said they were concerned that the system sometimes had led to inadequate staffing in important areas like critical care. In one measure of adequate staffing — the prevalence of bedsores in patients bedridden for long periods of time — HCA clearly struggled. Some of its hospitals fended off lawsuits over the problem in recent years, and were admonished by regulators over staffing issues more than once.

‘Through the Roof’

Many doctors interviewed at various HCA facilities said they had felt increased pressure to focus on profits under the private equity ownership. “Their profits are going through the roof, but, unfortunately, it’s occurring at the expense of patients,” said Dr. Abraham Awwad, a kidney specialist in St. Petersburg, Fla., whose complaints over the safety of the dialysis programs at two HCA-owned hospitals prompted state investigations.

One facility was fined $8,000 in 2008 and $14,000 last year for delaying the start of dialysis in patients, not administering physician-prescribed drugs and not documenting whether ordered tests had been performed.

Claiming he provided poor care, the other hospital did not renew Dr. Awwad’s privileges. Dr. Awwad is suing to have them reinstated. HCA declined to comment. HCA says it stands by its procedures, billing practices and level of care.

HCA says that more than 80 percent of its hospitals ranked among the top 10 percent in the country for federal quality measures, compared with 13 percent in 2006 when it went private. Last year, the company provided a $2.68 billion provision for charity care. And under the control of its private equity owners, HCA has invested around $8 billion in its hospitals in the last five years, according to Securities and Exchange Commission findings.

“You must know that we firmly believe that there is no sustainable business model as a health care delivery system that does not have at its core the provision of high-quality patient care and services,” HCA’s chief executive, Richard M. Bracken, wrote in an e-mail to The New York Times last year. Achieving a balance between profit and care is harder for investor-owned hospitals like HCA than for others, some experts say. “If you were a for-profit hospital with investors and shareholders,” said Paul Levy, a former nonprofit hospital executive in Boston unaffiliated with HCA, “there would be a natural tendency to be more aggressive and to seek more revenues.” Executives at profit-making hospitals are “judged in greater measure by profitability” than the administrators of nonprofit hospitals, he said.