Photo: ODT files
The frail 63-year-old Gordon McLean, with schizophrenia and dementia, went missing from the hospital on October 12.
In January, Southern District Health Board mental health general manager Louise Travers called Mr McLean's disappearance a serious event and said the board had commissioned an external review, scheduled for March this year.
But Ms Travers said on Monday the external review was still under way.
"This is likely to take some time and we're unable to give an indication of when the review will be completed."
Police failed to find any sign of Mr McLean during an intensive search of the area where he was last seen.
A police spokeswoman said Mr McLean's file was still open.
