Search for missing elderly man Peter Roach scaled back in Rockhampton

Peter Roach, 80, was a patient at Rockhampton Hospital when he went missing on Sunday.  (Supplied: Queensland Police)

A land, water and air search for an elderly, non-verbal man has been scaled down five days after he went missing from hospital. 

Peter Roach, 80, was reported missing on Sunday and was last seen walking along Canning Street, near Rockhampton Hospital, that afternoon.

Police said Mr Roach has one arm, and a medical condition that can cause confusion.

The Central Queensland Hospital and Health Service (CQHHS) said as soon as Mr Roach was discovered missing from hospital on Sunday, staff alerted emergency services and next of kin.

Police launched a large-scale search on Monday involving dozens of SES volunteers, boats and a helicopter.

The Capricorn Helicopter Rescue Service has been searching the area in south Rockhampton.  (ABC Capricornia: Michelle Gately)

By Wednesday, the search was focused on the rural land and creeks on the outskirts of Rockhampton's CBD with police on dirt bikes and stock squad officers on horseback also called in.

“Other search methods including residential door knocks have also been undertaken, however, all efforts have failed to locate Peter,” police said in a statement issued to the media on Friday morning.

'Incredibly distressing'

Keppel MP and Assistant Health Minister Brittany Lauga said "there absolutely should be" an investigation into how Mr Roach left the hospital.

"It has been incredibly distressing for the team at the hospital," she said.

"They do everything in their power to help keep people safe and to help improve their health."

Ms Lauga thanked hospital staff, emergency services and SES crews for their work in searching for Mr Roach.

SES search creeks in Rockhampton for missing man Peter Roach.  (ABC Capricornia: Michelle Gately)

LNP Shadow Health Minister Ros Bates said her thoughts were with Mr Roach's family, and "patient safety and transparency" in the health system must be the top priority.

CQHHS said it would conduct a review of what happened.

"We are constantly seeking to improve our service, and when incidents do happen, we review them to determine if lessons can be learned," CQHHS general manager of Rockhampton Allison Cassidy  said.

Police are still encouraging Rockhampton residents and members of the public to thoroughly check their properties for Mr Roach, and to report any potential sightings to police.