Nearly 12,000 people die needlessly in hospital every year, according to findings published in the British Medical Journal.
Almost 1,000 patients are dying needlessly in NHS hospitals every month because of botched care, according to a new study.
Researchers found evidence that patients are being misdiagnosed, prescribed the wrong drugs, or given inadequate fluid replacement.
Others were poorly monitored, the doctors warn.
The research was revealed just a day after a coroner strongly criticised medical staff who let a patient on a hospital ward die from dehydration.