Fewer people would die in hospital if accident and emergency care was centralised at one site, according to a report by NHS bosses.
Higher than average mortality rates at Calderdale and Huddersfield NHS Foundation Trust are listed among reasons that services need to be reorganised.
NHS trusts use a measure called the Hospitals Standardised Mortality Ratio (HSMR) to record death rates in hospital.
Calderdale and Huddersfield’s HSMR is currently 113, against a target of 100 - which means the mortality rate is 13 per higher than would be expected.
HSMR is a crude mortality measure and the only way of finding out if a death could have been avoided is by reviewing individual cases.
But the report by Calderdale and Huddersfield Clinical Commissioning Groups (CCGs) said: “Too many people are dying in our hospitals. The hospital Standardised Mortality Rate is higher than the England average.”
The report said patients were also staying in hospital longer than is necessary and too many were being re-admitted within 30 days of discharge.
NHS bosses want to cut the numbers of people admitted to hospital with long-term conditions and those waiting for more than five weeks for diagnostic tests.
For A&E services, the report said future plans were for a single emergency care centre to “maximise the chances of survival and a good recovery”.
The report said: “Additionally, there is a wealth of evidence that centralising some services can save lives.
“Lives have already been saved as a result of centralising stroke and major trauma services on a West Yorkshire basis.”
Read more about the A&E proposals at Calderdale Royal Hospital and Huddersfield Royal Infirmary: