NEW guidelines for recording hospital deaths are to be introduced after a health board held back more than 50 reports.
Health Secretary Nicola Sturgeon ordered NHS Ayrshire and Arran to "urgently review" its FOI policy following the breach.
The failings emerged after Rab Wilson, who worked for NHS Ayrshire and Arran, asked the health board for copies of all its "critical incident" reviews and significant "adverse event" reports which are used to investigate incidents, improve safety and patient care and minimise risk.
Mr Wilson turned to Information Commissioner Kevin Dunion when the health board claimed it did not hold any such reports, apart from one it had already given to him.
But when the commissioner investigated, 56 reports were found on a computer.
The health board has put in place a detailed action plan to update FOI procedures following an investigation by Healthcare Improvement Scotland (HIS).
A new national framework for managing and learning from adverse events in the NHS will also be put in place across Scotland.
Ms Sturgeon said: "NHS Ayrshire and Arran will be taking forward actions to respond to the recommendations of this review as a matter of urgency and have already put in place a detailed improvement plan.
"It is vital lessons are learned from adverse events to improve patient safety and the quality of healthcare services. All Boards must consider the recommendations from the report and the development of the new national framework.
"Healthcare Improvement Scotland will undertake a programme of reviews over the next 12 months to ensure appropriate action has taken place."