Daeppen J-B., Bertholet N., Gaume J. et al.
Drug and Alcohol Dependence: 2011, 113, p. 69–75.
Unable to obtain a copy by clicking title? Try asking the author for a reprint by adapting this prepared e-mail or by writing to Dr Daeppen at Jean-Bernard.Daeppen@chuv.ch.
Binge drinkers among young Swiss men being conscripted in to the army responded to around 16 minutes of alcohol advice by on average cutting their intake 20% more than recruits whose drinking was simply assessed, a rare demonstration of the impact of a brief intervention in an unselected population.
Summary All Swiss men aged 20 are subject to conscription in to the army via an assessment of their fitness to serve, offering this study a chance to test a brief alcohol intervention among a representative sample of young men rather than the more typically studied college or patient populations, and to deliver the intervention across the board, not just to identified heavy drinkers. The site was an army intake centre serving the French-speaking part of Switzerland. Conducted along motivational interviewing lines, the intervention's aim was both to reinforce the behaviour of low-risk drinkers and to moderate that of conscripts drinking heavily.
At the centre 622 conscripts were randomly allocated to complete baseline self-completion assessment questionnaires (the control A group of people, households, organisations, communities or other units who do not participate in the intervention(s) being evaluated. Instead, they receive no intervention or none relevant to the outcomes being assessed, carry on as usual, or receive an alternative intervention (for the latter the term comparison group may be preferable). Outcome measures taken from the controls form the benchmark against which changes in the intervention group(s) are compared to determine whether the intervention had an impact and whether this is statistically significant. Comparability between control and intervention groups is essential. Normally this is best achieved by randomly allocating research participants to the different groups. Alternatives include sequentially selecting participants for one then the other group(s), or deliberately selecting similar set of participants for each group. group), or to these plus an immediate intervention. Largely because of competing army recruitment requirements, just 418 completed the assessment/intervention phase of the study, of whom nearly 90% could be re-assessed over the phone about six months later to check the impact of the intervention. Generally lasting 10 to 20 minutes, this consisted of an individual face-to-face session in a private room, during which the counsellor explored drinking and related hazardous behaviours and the conscript's own drinking. The aim was to generate a perspective from which the young men would consider curbing their drinking and/or associated risks or harms, and to do so in the nonjudgmental, empathic, and collaborative manner characteristic of motivational interviewing. Rather than a set programme, counsellors drew on a menu of strategies adapted to each individual. Unlike many other studies, the counsellor did not know the assessment results so could not attempt to foster motivation by feeding these back to the conscript. However, the counselling strategy included an initial exploration of the conscript's drinking. Researchers and counsellors stressed their independence from the army and the confidentiality of the sessions and assessments. Among the supports offered the two counsellors was weekly supervision based on audiotaped sessions.
Among this population risky drinking typically takes the form of episodic heavy consumption ('bingeing') rather than daily excessive use. For the purposes of the study, recruits were considered 'bingers' if at intake they typically drank 60gm (nearly eight UK units) or more of alcohol during the same drinking session at least once a month. Nearly two thirds met this criterion. For these young men the aim was to curtail their risky drinking. Despite on average their feeling little need or impetus to do so, in this the intervention was modestly successful. Six months later 'bingers' in the intervention group had cut their average weekly alcohol intake of 113gm (14 UK units) by about 15gm (two UK units) compared to an 8gm rise in the control group. The intervention group also reduced the number of times they binged from on average 4 to 2.5 times a month, twice the reduction made by the control group. When these results were adjusted for differences between the groups at intake, the reduction in weekly drinking was estimated at 20% more than in the control group and remained statistically significant. However, though of roughly the same magnitude, the reduction in binge drinking episodes was not statistically significant.
In contrast, there was no impact among conscripts drinking below the binge-drinking level. Their low-risk drinking Consisting by definition of a heavy session typically less than once a month but also in practice very light drinking amounting to about two to four UK units a week. was generally sustained six months later and to roughly the same degree whether or not they had been allocated to the motivational interview.
This study showed that young men who are typical of the general population and initially not much inclined to curb their drinking will on average nevertheless do so after brief counselling based on motivational interviewing, suggesting that this approach does (as intended) promote 'intrinsic' motivation which leads to meaningful behaviour change. It also shows that this can happen without personalised feedback of assessment results and that this effect is additional to any impact of assessment.
commentary This study was one of two used in a previous report to identify the active ingredients of brief motivational alcohol interventions. In line with other studies, and with the theory underlying the approach, this analysis found that counsellor comments consistent with motivational interviewing were especially often followed by 'change talk' indicative of a willingness or intention to curb drinking, while inconsistent comments tended to be followed by counter-change talk. In finer detail, the most powerful active ingredient appeared to be the counsellor's reflections back of what the client had said or seemed to be feeling. Since change talk has been associated with actual change, the implication is that these reflections helped promote the changes the counsellor was seeking – to curb excessive drinking or control resultant risks and harms. However, in this study (though there have been in others) there was no investigation of whether change talk really was associated with corresponding changes in drinking. These and some other findings are consistent with the proposition that effective motivational interviewing stimulates change by leading the client themselves to voice an intention (or the precursors of an intention) to change.
Assuming this was indeed how the studied intervention worked, from the featured report we now know that these strategies were modestly successful in curbing the consumption and perhaps also the binge-drinking patterns of young men who met the study's criterion for binge drinking. Importantly such effects have now been demonstrated in an unselected, Few conscripts refused to join the study or failed to complete the initial procedures and the follow-up rate was high. representative population rather than as is typical in primary care studies, among a selected set of practices willing to try the approach and a selected set of patients willing to participate in the trial. As the authors speculated, there is reason to believe that the counselling would have been more effective had the results of the prior assessment been fed back to the conscript and used to generate motivation to adopt (for those to whom this applied) a less atypical drinking pattern.
What is unclear from research to date is whether brief interventions based on motivational interviewing are any more effective than other approaches such as straightforward advice to cut one's consumption. The clinical significance of the average weekly consumption cut from 113gm to 98gm seen in the study is also unclear. Among European men, within this range deaths from whatever cause vary little, but in finer grain this verdict may not apply to deaths or injury among men around 20 years of age, especially those related to intoxication rather than steady excessive drinking.
One concern about the study is that the criterion for 'binge' drinking was decided not in advance of the data being gathered but afterwards, opening up the possibility that it was artificially set at a level which generated statistically significant results, in turn casting doubt Post-hoc (ie, after the data has been gathered) subsample analyses of this kind are best seen as generating hypotheses for testing in a study specially designed for this purpose. The main problems are that they rob the results of the reassurance of the level playing field created by randomising patients to different treatments, they build on what may be chance variation in the effectiveness of the intervention between different subsamples, test effects not derived from the theory of how the intervention is supposed to work, and (there is no implication that this was a problem in this case) can capitalise on the fact that samples can be sub-sampled in any number of ways until one (perhaps purely by chance) results in a significant finding. As a result, "any conclusion of treatment efficacy (or lack thereof ) or safety based solely on exploratory subgroup analyses are unlikely to be accepted" (Lewis J.A. "Statistical principles for clinical trials (ICH E9): an introductory note on an international guideline." Statistics in Medicine: 1999, 18, p. 1903–1904. http://www3.interscience.wiley.com/journal/63000985/abstract?CRETRY=1&SRETRY=0. These risks are eliminated or reduced by specifying the subsamples in advance at the time the trial is designed but often this is not the case (Al-Marzouki S., Roberts I. "Selective reporting in clinical trials: analysis of trial protocols accepted by The Lancet." The Lancet: 2008, 372, 19 July, p. 201). over the reliability of the findings. Certainly this criterion differed from the definition In the earlier report at-risk alcohol use was defined as more than 210gm of alcohol – about 26 UK units – a week or the consumption at least twice a month of 60gm or more in a single drinking episode. Binge drinkers in the featured report only had to exceed 60gm once a month. of at-risk alcohol use used by the same research team in an earlier analysis of results from the same study.
Thanks for their comments on this entry in draft to Jean-Bernard Daeppen of the University of Lausanne in Switzerland. Commentators bear no responsibility for the text including the interpretations and any remaining errors.
Last revised 25 February 2011
REVIEW 2015 Prevention of addictive behaviours