Walters S.T., Vader A.M., Harris T.R.
Journal of Consulting and Clinical Psychology: 2009, 77(1), p. 64–73.
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Brief interventions based on motivational interviewing typically incorporate feedback on the individual's risk and use level compared to the norm, but does this really help? A US college study found it did, the combination leading to greater drinking reductions than either on its own.
Summary Motivational interviewing is a counselling style shown to reduce heavy drinking among college students and in treatment contexts. Most college studies have combined feedback Typically including presentation of information on personal drinking patterns, comparisons with national and/or college drinking norms, risk factors for heavy drinking, and negative consequences experienced as a result of heavy drinking from an assessment of the student's drinking profile with a motivational interviewing style of discussing this information. This study aimed to identify the active ingredients of such an intervention by 'dismantling' it in to these two components.
Students at a US university were recruited For their participation, students could receive $20 or an extra psychology course credit at each assessment and for attending the in-person session (if so assigned). through posters, presentations and direct e-mail invitations. Of an estimated 675 heavy drinkers among those invited, 279 agreed to participate after qualifying for the study by completing screening procedures and admitting to at least one heavy-drinking episode in the past fortnight. They averaged about 27 UK units of alcohol a week. All the students completed an assessment of their drinking and related problems. For a randomly selected 1 in 4, this was the sole 'intervention'. The remainder were randomly allocated to receive: immediate computerised assessment feedback with no further intervention; the same feedback delivered later and discussed face to face during a single-session motivational interview typically lasting under an hour; or a similar motivational interview but without the feedback. The counsellors were specially trained, and supervised with the aid of session videos.
Merely being assessed was followed six months The same measures were also taken at three months. For clarity this account focuses on changes at six months. later by small reductions in a composite measure of drinking intensity and problems and also in the components Consisting of the number of drinks students said they consumed over the past month, an estimate of the highest blood alcohol level reached in their heaviest drinking episode during that period, and reported alcohol-related problems in the past three months. of this measure. Against this benchmark, only the motivational interview incorporating feedback led to significantly greater reductions. For example, after this, on average drinks per week had fallen by an extra 9 UK units. In contrast, when the interview had not incorporated feedback, the extra reduction over and above assessment amounted to just over half a unit. Supplementing assessment with computerised feedback alone was similarly ineffective, leading to no further reduction in drinks per week. Confirming its superiority, when the three active interventions were compared with each other, motivational interviewing incorporating feedback led to the greatest reductions in drinking and (compared to motivational interview without feedback) in drink-related problems, all statistically significantly advantages.
Further analysis suggested that much of the extra impact of the combined intervention was due to correcting the students' over-estimates of how many same-sex students in the USA drank more than they did. On the basis of their work and earlier studies, the authors concluded that feedback-based motivational interviewing appeared to be a robust intervention for reducing drinking among this population.
commentary The message seems to be that among this kind of population (not seeking treatment, but interested enough to participate in a study; moderately heavy socially integrated drinkers), giving individuals 'normative' feedback on how their drinking and risk levels compare to those of their peers is an important but insufficient ingredient. Reinforcing and exploring the implications of this information in the course of a motivational interview gave it greater resonance, seemingly depriving these heavy drinking students of the comforting assumption that they were merely average drinkers. Faced with this identity challenge and/or relieved of presumed social pressure to drink heavily, the tendency was to cut back. Conversely, without feedback to focus and justify the discussion, motivational interviewing was less effective. The interpersonal style and the information content complemented each other.
In this particular study a minor concern is that by chance students allocated to motivational interviewing plus feedback started off being slightly heavier and more problematic drinkers; part of the apparent advantages of this approach may have been due to them reverting naturally to more typical levels. However, the study's verdict has been broadly confirmed by related studies and by reviews of all the available research. This body of work is summarised and selected from below. For details Background notes.
Only one other (smaller and more short-term) analysis has, within the same study, compared assessment feedback alone against motivational interviewing with and without feedback. In line with the featured study, its tentative conclusion was that in respect of drink-related problems, motivational interviewing benefited from assessment feedback. It also found that if it came to a choice between unelaborated feedback and motivational interviewing without feedback, the former more effectively reduced dependence symptoms. In the featured study too, feedback seemed slightly the better option of the two, though neither significantly bettered assessment without any intervention.
Four previous studies contrasted feedback alone with feedback incorporated in a motivational interview. All concerned risky drinkers identified through screening. College samples either volunteered for the studies and received course credits or financial compensation, or were mandated to the intervention for violating alcohol-related college rules. In two studies emergency ward patients were screened. Taken together, these studies (all but one from the USA) suggest impacts are maximised by a motivational interview based partly on feedback from an assessment of the individual's risks and how their drinking compares to national or local norms.
This is not to say that mere feedback is ineffective. As in the featured study, in many previous studies it failed to create statistically significant changes. But when those studies (almost entirely of non-treatment seeking drinkers and mainly of students) were aggregated, a small to medium sized reduction in alcohol consumption was detected.
All these studies left open the question of whether other counselling/information-giving styles might have been just as effective as motivational interviewing. That issue was addressed in three reviews including one which aggregated results from 62 studies evaluating attempts to curb risky drinking among college students. Verdicts were similar, though with some variations. Where they overlapped was in concluding that among the interventions with the strongest research backing were individual, face-to-face discussions which adopted a motivational interviewing style, and which featured personalised feedback on the individual's drinking profile – in particular, 'normative' feedback setting their drinking and/or risks alongside national or local norms.
It should not however be concluded that these are sure-fire ways to curb excessive drinking. It remains unclear whether broader college populations unwilling to volunteer for such studies (sometimes only a minority do) or with a different motivation for accepting such interventions (the normal enticements are cash or course credits) would have reacted in the same ways. And normative feedback is limited by the fact that the most influential comparators are the people socially closest to the individual. For heavy drinkers, commonly their closest friends really are heavy drinkers. There is no misperception to correct. Rather than being a prompt to cut back, confirming that they and their friends drink more than normal may be the kind of distinction they desire. This is one reason why universal norms-based campaigns can fail. Such complications can be more sensitively handled in the individualised and flexible format of a motivational interview.
Thanks for their comments on this entry in draft to Jim McCambridge of the Centre for Research on Drugs and Health Behaviour at the London School of Hygiene & Tropical Medicine. Commentators bear no responsibility for the text including the interpretations and any remaining errors.
Last revised 05 March 2009
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