Objective: To determine any impact associated with changes to liquor licensing regulations on emergency department attendances for alcohol-related serious injuries in an inner-city entertainment precinct.

Design, setting and participants: A blinded retrospective analysis of data from the Emergency Department Information System (EDIS) of the major trauma and teaching hospital (St Vincent's Hospital, Darlinghurst) in the Sydney CBD Entertainment Precinct. Data for trauma cases classified as Australasian triage categories 1 (immediately life-threatening) and 2 (imminently life-threatening, important time-critical treatment, very severe pain) in the 12 months before (24 February 2013 - 23 February 2014; period 1) and the 12 months after (24 February 2014 - 23 February 2015; period 2) the 2014 changes to liquor licensing regulations applied to the precinct.

Main outcome measures: Critically or seriously injured emergency presentations that were identified as related to alcohol use.

Results: In the 2-year study period, there were 13 110 triage category 1 and 2 presentations to the St Vincent's Hospital emergency department: 6467 during period 1 and 6643 during period 2. Of these, 1564 (4.3%) were patients who presented with alcohol-related serious injuries: 318 (4.9%) during period 1 and 246 (3.7%) during period 2 (P < 0.05). The proportion of alcohol-related serious injury presentations (triage categories 1 and 2) was much higher (9.1% of presentations) during the high alcohol time (HAT; 6 pm Friday to 6 am Sunday) than during the rest of the week (3.1%). After the introduction of the regulatory changes, there was a significant decrease in the number of seriously injured patients during HAT, from 140 presentations (10.4% of presentations) before the change to 106 (7.8%) after their introduction, a relative reduction of 24.8% (P < 0.05). There was a small increase in the number of patients presenting with alcohol-related injuries between 9 pm and midnight.

Conclusions: There was a significant reduction in the number of alcohol-related serious injury and trauma presentations to the emergency department in the 12 months after the introduction of the new liquor regulations. This change was seen throughout the week, but was especially marked at weekends.