The stark variation in death rates at NHS hospitals has been laid bare by a new analysis that reports “worryingly high” mortality figures at a dozen trusts across England.

Dr Foster Intelligence’s hospital guide 2012, which assessed 145 trusts in England against four key mortality measures, praised five trusts for their low death rates but warned that others were performing below expectations.

The measures used were the hospital standardised mortality ratio, which measures deaths in hospital; the summary hospital level mortality indicator, which measures in-hospital mortality and deaths outside hospital within 30 days of discharge; deaths after surgery …