WA operating theatres must do better: AG

At least 3000 hours of spare operating theatre time could have been used to treat many more patients across five West Australian hospitals last year, the auditor general says.

Time was lost because more than a third of sessions did not start when scheduled, many did not finish on time and 1244 elective cases were cancelled on the day of surgery.

Auditor General Colin Murphy said the lost hours were equivalent to staffing two theatres for almost a year without treating any patients.

Mr Murphy said efforts to improve efficiency was often ad hoc with limited analysis of existing data guiding decisions.

"Better scheduling of surgery would allow more available time to be used, and reduce the need for and cost of staff working overtime," he said.

"Efficient theatres save money and help hospitals to minimise the time patients have to wait for surgery."

Mr Murphy said the Department of Health was taking steps to improve efficiency.

WA has 112 operating theatres across 32 public hospitals, plus additional theatres at two privately operated public hospitals.

More than 81,000 elective surgery cases and thousands of emergency surgeries were performed in 2014-15.