Death rates at a dozen hospital trusts in England went well beyond normal levels last year, prompting fears that patient safety is being compromised.
Alarm bells rang today amid growing concerns that there could be "another Mid Staffs" as hospitals are increasingly focusing on cost of care rather than quality of care, the Dr Foster Hospital Guide found.
Each of the 12 trusts fell short on two of four mortality rate indicators, which include deaths after surgery and the deaths of patients who were admitted for minor ailments or "low-risk conditions."
The report stated: "These measures are to be used as a warning sign that poor-quality care may be leading to a higher-than-expected mortality.
"With the rising demand for care and falling revenues, there are concerns that trusts will focus more (or exclusively) on cost of care rather than quality of care.
"Because of this, there is a fear that there could be another Mid Staffs. Hospital managers must ensure that they do not sacrifice one for the other."
The report also found that the safety of patients is also being risked because hospitals are "full to bursting," with many regularly breaching the 85 per cent limit set in place as a safeguard.
Shadow health secretary Andy Burnham said: "Savage cuts to council care budgets are making it harder for hospitals to discharge patients, which results in pressure on beds backing up through A&E.
"It is why we hear stories all over England of ambulances queuing outside A&E departments unable to hand over patients.
"Unacceptable risks are being taken with patient care as the NHS struggles with the toxic combination of reorganisation and real-terms cuts."