Plymouth's Derriford Hospital has lost one star

Eight out of 20 have lost a star since last year and three have gained one.

The Cornwall Partnership Trust, which cares for people with mental health problems, is the only Cornish health trust to improve its performance.

East Devon Primary Care Trust and Northern Devon Healthcare Trust both go up to the maximum three stars.

Key targets

Plymouth Hospitals Trust has lost a star since last year and is down to one, largely due to mounting debts.

It met eight out of nine key targets but, with an overspend of �7.75m, significantly underachieved on financial management.

Plymouth Hospitals Trust Medical Director Terence Lewis said: "The other indicators that were measured, we were at there or better than there.

"But the finances have been a real problem. They're very important and we're doing our level best to get back into financial order."

The Cornwall Partnership Trust went up to a three star rating.

The star ratings, published by the Healthcare Commission, assess the performance of health trusts across a range of areas, including meeting government targets, the experience of patients and the way they are managed.

Westcountry Ambulance Trust and five primary care trusts in Devon have lost a star and are down to two.

The Cornwall Partnership Trust went up to a three star rating, while North and East Cornwall and West Cornwall PCTs now have one star each.

Primary Care Trusts in Plymouth and north Devon remain on two stars, as does the mental health provider, Devon Partnership Trust.