The standards of care at the 14 hospital trusts with the worst death rates have been investigated.
The review led by NHS England medical director Sir Bruce Keogh looked at whether the figures were being caused by failings beyond those that have already been identified by regulators. Eleven of the trusts under investigation have been placed on special measures.
Here is a breakdown of what has been said about each.
Basildon and Thurrock University Hospitals NHS Foundation Trust
Criticised for having seven "never events" in three years. These are serious, largely preventable patient safety incidents, such as leaving behind swabs or surgical instruments in patients, that should not occur if the available preventative measures have been implemented.
Also criticised for its infection control measures and staffing levels.
Sir Bruce's report says the Trust's historical culture has been focused on financial targets and the tone from the top now needs to focus on improving quality and long term sustainability.
Buckinghamshire Healthcare NHS Trust
Shortcomings include nursing staff failures in dealing with patients nutritional and medication needs.
Complaints from families about how patients with dementia were treated.
The report highlighted a concern over staffing levels of senior grades, in particular out of hours.
The Trust has recently undergone significant change, most notably the consolidation of the A&E department from Wycombe to the Stoke Mandeville site and the creation of three large organisational divisions from the original six. The review said the Trust need to "provide assurance" on the impact of this.
Burton Hospitals NHS Foundation Trust
Concerns about safety as staff were found to be working for 12 days in a row with no break.
Allegations that death certificates were not being completed in line with the Trust's procedures.
Examples of poor communication with patients and staff, particularly junior doctors, many of whom felt unsupported
East Lancashire Hospitals NHS Trust
Criticised for poor governance, inadequate staffing levels at weekends and for staff "talking down" to patients and their families when they voiced concerns.
Sir Bruce's report said the Trust's complaints process was "poor and lacking a compassionate approach".
The panel identified a high level of still born babies in March 2013 but this had not been escalated to the Board or investigated. The Trust is now investigating this and is setting clearer procedures for triggering escalation.
George Eliot Hospital NHS Trust
Criticised for its out of hours care and for its poor track record on bed sores.
The panel also noted that patients were often shifted from ward to ward - multiple bed moves were not uncommon during a patient stay.
Medway NHS Foundation Trust
Criticised for poor communication with patients, poor management of deteriorating patients, inappropriate referrals, delayed discharges and long waits in A&E.
North Cumbria University Hospitals NHS Trust (Two hospitals - Cumberland Infirmary and West Cumberland)
Criticised for poor maintenance of two of its operating theatres which were closed immediately.
Northern Lincolnshire and Goole Hospitals NHS Foundation Trust (Three hospitals - Diana, Princess of Wales Hospital, Goole and District Hospital and Scunthorpe General)
Criticised for inadequate staffing levels and over-reliance on locum cover in some areas of the Trust.
Criticised for its out of hours stroke services at Diana, Princess of Wales Hospital.
The Trust's provision of patient dignity was also questioned - the review panel witnessed a patient who was inappropriately exposed where there were both male and female patients present.
Sherwood Forest Hospitals NHS Foundation Trust
Significant concerns around staffing levels at both King's Mill Hospital and Newark Hospital and around the nursing skill mix, with trained to untrained nurse ratios considered low, at 50:50 on the general wards.
Poor attention paid to oral hygiene.
Patient dissatisfaction. Feedback from patients treated by the trust revealed many were left unaware who was caring for them. And bedside buzzers often went unanswered.
Tameside Hospital NHS Foundation Trust
Panel found a general culture of accepting suboptimal care.
Patients treated by the Trust reported being left on unmonitored trolleys for excessive periods of time.
Concerns about infection control policies.
United Lincolnshire Hospitals NHS Trust
Criticised for having 12 "never events" in three years and for its "Do Not Attempt Resuscitation" paperwork (which the Trust has since rectified).