Health professionals, police advocates and anti-alcohol campaigners have slammed a possible early review by the New South Wales government into its controversial lockout laws.

Ralph Kelly has been pushing for safer alcohol laws since his son Thomas died from a one-punch assault in Sydney's Kings Cross.

He says the New South Wales government assured him in September that the lockout laws wouldn't change before 2016.

"We've seen prior to 2013 what happens in this state - Sydney was a dangerous place," he said.

"Since the lockout laws, we've seen good results in 2014. People should come before power and money. Simple as that."

The Acting NSW Premier Troy Grant told 2GB radio the commitment still stands, but part of that commitment was to review the lockout laws after they'd been in place for 12 months.

"The review can commence and we can start gathering all the data from 12 months out so we've got a full year of data that will help ultimately the statutory review," he said. 

"There's no indication whether things will change in any direction. The evidence will tell government what we need to do as will the community.

"Mr Kelly and the community up there have nothing to fear and anyone who's got an alternate view will have every opportunity to present the evidence."

The laws require licensed premises in central Sydney and Kings Cross to refuse entry to patrons after 1:30am, and stop serving alcohol at 3am.

Mr Kelly held a joint press-conference with St. Vincent's Hospital's Dr Tony Grabs, who noticed significant changes since the laws came into place.

"We've seen probably a 50 per cent reduction in the number of people coming through the emergency department that have severe intoxication or as victims of violence in association with alcohol," Dr Grabs said.

"We've been very pleased with the results so far. Our nursing staff are feeling it, our doctors are feeling it, and our emergency department is a different place on a Saturday morning and a Sunday morning after events of the night before."

Dr Grabs was joined by the Royal Australasian College of Surgeons and the New South Wales Police Association.

They say the laws not only work, but should be adopted across Australia.

 Scott Weber from the NSW Police Association said that if the government is going to do an early review, it should be to "actually increase the boundaries in regards to these restrictions".

"It should be across the state of New South Wales, and yes, Australia," he said.

"This saves lives." 

Similar schemes have been introduced in other cities, but none as stringent as Sydney's.

The number of Kings Cross revellers admitted to St Vincent's with serious head injuries has dropped 80 per cent and police say there's been a 40 per cent reduction in assaults after dark.

But a downturn is also being felt among the pubs and clubs themselves. 

The Kings Cross Liquor Accord said since these laws came into effect, up to 40 businesses have been forced to shut their doors.

They want a review to consider other factors that have been introduced to the area, its Chief Executive Doug Grand said.

"There's been a whole raft of improvements that have been made and what we're suggesting is they should be looked at in their totality to see what actually works without the blunt instrument of a lockout," he said.

"There's been more high visibility policing, that's improved a lot. There's more wayfinding, more signage, better lighting."

The government is waiting for the June release of data from the Bureau of Crime Statistics.