Common strategies, such as drinking slowly, using a designated driver, or alternating between water and cocktails, are largely ineffective at reducing alcohol consumption and harms from heavy drinking, a new study showed.

However, the meta-analysis of more than a dozen randomized controlled trials (RCTs) showed that these methods, called protective behavioral strategies (PBS), were linked to a small reduction in drinking frequency.

Over a longer follow-up period and in combination with other interventions, the strategies were also associated with reductions in alcohol quantity and frequency, but the overall effects were still small.

“Although increases in PBS may contribute to improved alcohol outcomes in some interventions, current RCT evidence does not support PBS as a sufficient or universal mechanism of alcohol behavior change,” investigator Patcharin Krongtham, PhD, and colleagues at Chulalongkorn University in Bangkok, Thailand, wrote.

The study was published in the latest print issue of Psychiatry Research.

Public Health Concern

Excessive drinking is a major public health problem in the US and is linked to roughly 178,000 deaths each year. Binge drinking is the most common form of excessive alcohol intake, particularly among young adults.

PBS are commonly used in self-administered interventions to reduce alcohol consumption and alcohol-related problems. However, the evidence that these strategies work as a stand-alone method is limited.

To better understand the effectiveness of PBS, the investigators conducted a systematic review and meta-analysis of 15 RCTs published between 2007 and 2023 that examined the strategies in adults.

PBS were divided into three main categories: limiting or stopping drinks, consumption pattern changes (such as drinking slowly), and harm reduction (such as using a designated driver).

The primary outcomes were the frequency and quantity of alcohol consumption and physical, social, or psychological alcohol-related harms. The secondary outcomes included the use of PBS, adherence, willingness to change, satisfaction, and self-efficacy.

There was a wide variety in how PBS were delivered across studies, with most using multiple categories of PBS. A total of 11 studies assessed a combination of limiting drinks, changing drinking patterns, and harm reduction, and the remaining four assessed selective avoidance and alternative strategies.

Almost half of the studies evaluated PBS as a secondary intervention. PBS were typically employed in one session or in short format, mainly online.

Strategies to Reduce Harm?

The PBS intervention did not lead to a significant uptake in the use of such strategies (P = .152). However, after removing an outlier study, the uptake was small but significant (P = .005).

However, PBS were not associated with a meaningful reduction in how much the participants drank (P = .162). PBS were linked to a significant reduction in alcohol consumption frequency, but the effect was small (P = .014).

Researchers found no significant link between use of PBS and a reduction in alcohol-related problems (P = .052).

After follow-ups ≤ 3 months, there were no significant effects associated with PBS on alcohol outcomes, but after longer follow-ups, small but significant decreases in alcohol quantity (P = .004) and frequency (P = .003) were observed.

Effects also differed by the mode of PBS intervention. When employed as a secondary method alongside other interventions, PBS were tied to a small but significant decrease in alcohol quantity (P = .040) and frequency (P < .001).

When PBS were the primary intervention, they were not linked to a significant effect on alcohol quantity and showed nonsignificant effects on alcohol-related harms. However, the authors noted that this subgroup analysis should be interpreted with caution given the limited number of studies.

“The current evidence suggests that PBS function most effectively as complementary behavioral tools embedded within broader motivational, self-regulatory, and contextual processes rather than as standalone mechanisms of change,” the authors wrote.

A Culture of Excessive Drinking

The sample population was mostly young US college students, limiting the generalizability of the findings. Another limitation was that the studies varied widely in terms of the focus on PBS, treatment intensity, sample sizes, and duration of follow-up, Andrea King, PhD, who was not involved in the study, told Medscape Medical News.

“There is a place for PBS as they are the nuts and bolts of ‘how’ to reduce drinking and plan for high-risk events,” King, professor of psychiatry and behavioral neuroscience at the University of Chicago in Chicago, said. These include learning how to monitor consumption and creating safe environments to limit harm.

“However, there are more forces at bay than this, with a culture of excessive drinking as the norm and positive expectancies of alcohol that are hard to derail in a single session or brief intervention,” she noted.

King’s research showed that people who experience heightened alcohol stimulation and reward are at a higher risk for future exacerbations in drinking and developing alcohol use disorder.

“So not all young drinkers are on the same playing field, and some may need more than a single-session or shorter-term intervention. Involving the larger community and parents is also important to address this highly complex problem,” she said.

Future trials assessing PBS in isolation are needed to identify which strategies are the most effective among different groups and drinking contexts, the authors noted.

King declared no relevant disclosures. This research was supported by the Ratchadaphiseksomphot Endowment Fund, Chulalongkorn University, and the Research grant for Systematic reviews and Meta-analyses from the Faculty of Nursing, Chulalongkorn University. Disclosures for study authors can be found in the original article.