The WLHD, which announced in July it had cut its budget deficit last year from $19.5 million in 2012-13 to $500,000 in 2013-14, did not confirm or deny the cuts.

The union said the WLHD was one of only two NSW health districts to cut nursing numbers.

"Data provided by the NSW Ministry of Health clearly indicates there has been a reduction of 57 full-time-equivalent nursing and midwifery positions across the Western NSW Local Health District (LHD) over the past 12 months (June 2013 to March 2014)," union spokeswoman Lisa Kremmer said.

Ms Kremmer said union members were shocked by the figures on job cuts "and alarmed there were no consultations in relation to the deliberate reductions".

"The association is concerned more cuts are likely to occur, impacting on the delivery of safe patient care throughout the LHD."

Health district CEO Scott McLachlan would neither confirm nor deny the cuts.

"Determining appropriate and equitable staffing levels has been a focus of the Health District over the last 12 months," Mr McLachlan said in a statement.

"This has been achieved through a review into staffing which aimed to ensure resources are matched to patient numbers at all sites.

"As a result of this review, some sites have had staff numbers increased and others decreased under more reliable and equitable staffing arrangements.

"There are processes in place to adjust staffing levels according to the activity in the facility as required."

Mr McLachlan said all parties were consulted during the reviews.

"The Health District has remained open and transparent about the review process and there has been extensive consultation with staff, unions and communities.

Every facility has been part of the review," he said.

Mr McLachlan said "new staffing arrangements" would not compromise patient care and safety.