Health chiefs have been ordered to explain why they have not shown they are acting on information provided by an NHS quality watchdog.

Western Isles Health Board is the only board not to have provided an "adequate" response to a project designed to improve the way health boards handle statistics, according to NHS Quality Improvement Scotland.

The board now has until December 11 to provide the watchdog with an update.

The move was disclosed when NHS QIS published a report today on how health boards responded to the project.

NHS QIS gave each board a "surgical profile" which is meant to be used to watch out for statistical variations which may be warning signs.

Today's report said the system had alerted NHS Fife to a relatively high rate of deep vein thrombosis in patients after they were admitted for general surgery at Queen Margaret Hospital, Dunfermline.

This alert enabled NHS Fife to review its data collection and guidance on thrombosis, and the rate has since fallen.

The system also flagged up a "relatively high" death rate in NHS Forth Valley during one quarter for a particular type of bladder operation, enabling new processes to be put in place for reviewing post-operative deaths.

The report said: "Only one health board, NHS Western Isles, has not provided an adequate response to the profile to demonstrate that it is using available data to stimulate reflection on, and improvements to, the services it provides for the population of the Western Isles.

"NHS QIS had therefore asked NHS Western Isles to carry out specific actions to investigate key patterns of data in its profile and to provide an update on these completed actions by December 11 2009."

The watchdog's chairman, Sir Graham Teasdale, said: "The surgical profiles project is having an increasing impact.

"It is helping to establish a culture throughout the NHS in Scotland whereby the people and organisations delivering patient care are using the data available to get a better understanding of the services they provide, including where improvements might be possible.

"This is clearly shown in the actions that NHS boards across Scotland have reported to us that they are carrying out in response to the profile. These cover a range of measures designed to improve the quality of patient care."