Effect of the online Rethink My Drink alcohol intervention on alcohol use and cognition in older adults in Australia: a randomised controlled trial

BACKGROUND: Alcohol use is increasing among older adults and is associated with cognitive impairment and dementia. The efficacy of scalable approaches to reduce alcohol use and related harms in older adults has not been tested. This study aimed to evaluate the efficacy of an online alcohol intervention in reducing alcohol use and cognitive decline in older adults. METHODS: We did a two-arm, parallel-group, randomised controlled trial online among community-based older adults (aged 60-75 years) who screened as having high-risk alcohol use (scoring ≥5 on the Alcohol Use Disorder Identification Test). Exclusion criteria included diagnosis of a neurological disorder (eg, dementia, Parkinson's disease, or multiple sclerosis), previous prescription of medication for the treatment of Alzheimer's disease, and non-correctable visual impairment. Participants across Australia were randomly assigned (1:1) to the Rethink My Drink programme (a four-module online intervention designed specifically for older adults) or an active control group (online information booklet), stratified by age and gender. Participants and the lead statistician were masked to group assignment. Number of drinks in the past month and global cognition Z scores assessed via the Cambridge Neuropsychological Test Automated Battery were the primary outcomes, assessed at the 12-month follow-up. Intention-to-treat analyses were conducted using generalised mixed effects regression. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12621000292875; March 16, 2021), and is completed. FINDINGS: Between Oct 29, 2021, and June 6, 2022, 3766 participants were screened for eligibility, 2878 were excluded (1390 did not meet inclusion criteria, 1047 declined to participate, and 441 had incomplete baseline assessments), and 888 completed baseline assessments and were randomly assigned. 448 participants were assigned to the Rethink My Drink intervention and 440 were assigned to receive the online patient information booklet. Data from 445 participants in the intervention group and 438 participants in the control group were analysed. Most participants (872 [99%] of 883) identified as White, 685 (78%) participants were female and 198 (22%) were male, and the mean age was 65·3 years (SD 3·9). At 12 months, those in the intervention group had greater reductions in their monthly number of standard drinks when compared with the control group (difference, 5·02 standard drinks [95% CI 1·81 to 8·24]; p