The number of people complaining about their treatment in hospitals is on the rise.

Brighton and Sussex University Hospitals' NHS Trust received 853 formal complaints between April 2005 and March this year, 46 more than the year before.

The trust is the largest in the county and runs the Royal Sussex County Hospital in Brighton and Princess Royal Hospital in Haywards Heath among others.

Managers say the increase is partly down to it encouraging people to report concerns and a reflection of increased worries about subjects such as MRSA infections.

The trust also hit national news last year when a Panorama programme revealed how an undercover nurse exposed shocking standards of care of elderly people on a ward at the Royal Sussex Hospital.

Overall the total number of complaints is less than one per cent of all patients seen and treated at the trust's hospitals.

Complaints covered a whole range of subjects including 274 made by people unhappy with all aspects of clinical treatment, 98 about the attitude of staff and 166 about delays and cancellations of outpatient appointments.

Director of nursing Alison Robertson said: "We have increased the amount of information available around the wards to encourage people to come forward if they have an issue they need to raise.

"These include notice boards on the wards and details of the person a relative, friend or patient should speak to if they have any concerns."

The trust is piloting a patients' diaries scheme later this year when people staying in hospital, and their relatives will fill in diaries about their experiences while in hospital.

Trust chairman Glynn Jones said: "It is important we get the message across that we want to hear from people if they have a complaint.

"We can't improve on things unless we know about it and then we can act on it. Recording the complaints also helps to monitor whether there is a particular theme that is recurring."

The trust says it does act on concerns raised and that has led to improvements in services.

A number of complaints were raised in the past from patients and the general public about staff wearing uniforms off-site which they felt could cause a risk of infection.

The trust's uniform policy has now been reviewed to ensure staff are aware uniform must not be worn off-site unless covered by an outer coat.

There have also been issues raised concerned with bereavement and care at the point of death.

It was found that some staff needed a refresher course in caring for the dying and their bereaved relatives and a new policy is being finalised.