A campaign to cut the number of life-threatening mistakes in the NHS in Wales has saved hundreds of lives, it is claimed.
Health service bosses say an estimated 410 lives were saved in the first six months of the two-year "1,000 Lives Campaign".
All NHS trusts and local health boards in Wales are taking part in the drive.
The aim is to improve patient safety by reducing mistakes and infections through better hygiene and care.
Dr Tony Jewell, chief medical officer for Wales, said the campaign was "clearly having an impact on clinical leadership and the quality of health care" in Wales.
"The changes that NHS staff are making to their working practices has not only made a difference to these lives that have been saved but those in the future who will benefit from these new ways of working," he said.
When the campaign was set up, organisers said at least one-in-10 patients were harmed unintentionally by their treatment.
Incidents range from minor allergic reactions to medication, to life-threatening mistakes in an operation.
Campaign director Dr Jonathon Gray said: "The commitment and engagement of NHS staff has been excellent.
"Alongside the good work already taking place, they have also developed new ways of working to deliver safer and better quality care to patients throughout Wales."
He said there was more work to do but was confident the aim of saving 1,000 lives by April 2010 would be reached.
Trusts and health boards are focusing on six main areas including reducing infections and surgical complications.
Changes include replacing razors with surgical clippers in all hospitals to reduce the chance of infections through nicks in the skin.
Efforts have been made to improve the design of wards to enable nurses to spend more time with patients.
Other improvements include better hand hygiene and fewer blood stream infections in intensive care units.
Changes have also taken place in primary care such as GPs working to improve the reliability of instructions given to patients, particularly with certain drugs.
The campaign has been welcomed by health professionals.
The Welsh secretary of the British Medical Association, Dr Richard Lewis, said: "Doctors will continue to contribute to the campaign's aims and highlight areas that require greater focus to make NHS Wales safer for all patients."