A team of researchers say Queensland's alcohol legislation needs revision for it to be effective, after a study into its impacts found more young people are pre-drinking before heading into night-time entertainment districts and violent assault rates remained unchanged.

The State Government brought in the legislation in 2016, in a bid to curb alcohol-fuelled violence in nightclub precincts in Queensland.

Pubs and clubs in night-club precincts were ordered to call last drinks at 3:00am instead of 5am and were banned from selling 'rapid intoxication drinks', like shots.

A three-year study from 2014 to a year after the changes, involving researchers from Griffith University, University of Queensland and Queensland University of Technology, has interviewed thousands of punters and taken blood alcohol readings.

Griffith University Associate Professor Grant Devilly told Hack since the legislation, patrons had increased their alcohol pre-drinking and entered night-time entertainment districts later.

"We found that people were more likely to have preloaded," he said.

"While before, 80 per cent of people preloaded, now it's 90 per cent and those who pre-loaded, their blood alcohol readings had gone up, so they were entering more drunk.

"If you have environments where almost everybody coming in has had quite a bit to drink, that's a worry."

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The study found assault rates, good order offences and general levels of fear in participants did not appear to have been affected by the legislation.

"It was surprising because the argument was that if we close down the alcohol sales from 5am to 3am that it was getting people out of the city when they hadn't had far too much," Mr Devilly said.

"When in fact because they were coming in more drunk they were still at the same levels."

A second round of liquor laws in 2017 which would have introduced a lock-out time of 1:00am was scrapped in favour of compulsory ID scanning in Safe Night Precincts.

Scanners have been blamed by many pubs and clubs, along with the Queensland Hotels Association as causing a big fall in patronage.

A review of the scanners is still underway.

A spokesman for the Attorney General told Hack: "The Government will consider the findings of Griffith's study in conjunction with other information available to us."

Associate Professor Devilly said any changes made in alcohol legislation should encourage people to come into the late-night districts earlier, to reduce 'pre-loading' and encourage the consumption of alcohol in a controlled environment.

"We need interventions to address the specific needs of the night-time economies in Queensland."