Studying individual-level factors relating to changes in alcohol and other drug use, and seeking treatment following Minimum Unit Pricing implementation

28 December 2020


Dr Mark McCann1, Dr Dominika Kwasnicka2, Dr Massoud Boroujerdi1, Dr Aileen O’Gorman3, Mr Martin Anderson1, Dr Peter Craig1, Mr David Liddell4

1 - MRC/CSO Social and Public Health Sciences Unit, University of Glasgow
2 – SWPS University of Social Sciences and Humanities, Wroclaw, Poland; and School of Psychology, Curtin University, Perth, Australia
3 - University of the West of Scotland, Paisley
4 – Scottish Drugs Forum, Glasgow

Key findings

  • This study used daily smartphone surveys, and qualitative interviews about social networks to study the individual-level factors related to alcohol behaviour change.
  • The predictors of behaviour varied from person to person, the most common factors were: situational availability of alcohol, mood, and adaptive responses to control alcohol use (motivation, implementing strategies to drink less).
  • There was a trend towards lower units per day after Minimum Unit Pricing (MUP) was implemented among some but not all participants.
  • While some reported no change in drinking, others reported losing access to low price alcohol when MUP was implemented.
  • No participants switched to using other drugs after MUP.
  • The mixed methods N of 1 design provides information on the variety of person-specific factors relating to alcohol use. This approach describes the potential processes which may aggregate to produce the population level effect of MUP. Other MUP evaluation studies are currently evaluating the overall effect of MUP.

Background and aims

The Scottish Government implemented legislation for Minimum Unit Pricing (MUP), meaning that alcohol cannot be sold to the public for less than 50 pence per unit of alcohol. The law came into effect on the 1 May 2018. MUP aims to reduce the harms caused by alcohol by lowering consumption among the heaviest drinkers. Other studies will evaluate Minimum Unit Pricing by looking at population level trends in consumption, and other factors that MUP may influence.

This project used innovative methods to understand the individual-level factors relating to alcohol use that cannot be observed looking at overall population trends. We aimed to look at the differences in alcohol consumption, other drug use, and contacting treatment services for alcohol dependence and whether the psychological and social factors that relate to these outcomes vary between individuals.


The Scottish Drugs Forum peer research team recruited participants to the study and administered all the study materials; obtaining consent, explaining how to operate the smartphone and complete the daily survey, maintaining contact throughout the study, safeguarding and signposting, and conducting follow up social network interviews. Participants were recruited via the peer team’s contacts within their local communities. These were partly drug and alcohol using communities, and also people in contact with treatment services, mutual aid or recovery groups. All recruits self-identified as “heavy drinkers” i.e. drinking to a level that is likely to harm health.

Those agreeing to take part completed a baseline survey then received daily surveys sent directly to their mobile phone for 12 weeks. There were three waves of 12-week survey periods. The first wave was a 12-week period before MUP, the second started before and finished after MUP, and the third started after MUP was implemented.

Participants received the same survey each day with questions in a random order each day, and with a comment box at the end of each survey asking them to add any information relevant to their drinking or general wellbeing. The questions were designed to capture information relevant to the last 24 hours, e.g. amount and type of alcohol consumed, stress, social contact.

Participants were invited for a final interview to talk about their experiences during the survey and to complete an egonet interview: a semi structured drawing task to collect information about people in their lives during the time they took part in the study.

We conducted statistical analysis of the daily survey data, as well a mixed methods analysis of the social network graphs, interview transcripts, and free text responses to the daily survey.


In total 25 participants took part in the study. On average, participants completed 27 daily surveys, but this varied from a single survey to over 80 days. For six respondents, alcohol was their only substance of dependent use, while six reported secondary dependence on substances other than alcohol. The majority of respondents (68%) lived alone, two were homeless and five reported having had no social contact in the previous six weeks.

The analysis found that the factors related to alcohol use varied widely from participant to participant, as did the factors relating to wellbeing among participants who were not drinking. Situational availability, mood, and factors relating to preventive responses to alcohol use (like motivation and effort) were the most commonly occurring factors. There was a trend towards lower units per day after MUP was implemented for some participants, this tended to be those who were drinking more before MUP.

In qualitative interviews, respondents reported how alcohol use could lead them to get into debt, regardless of the price.

“… it doesn’t matter where we find the money from … We don't worry about what consequences, what happens … it does is actually make matters worse. Because I'm having to find the money from elsewhere. And the only place to find it is either food, or not paying bills. And that comes back and bites you. But you don't worry about that, you hide from it, as long as you get that bottle.”

Other respondents texted information in during their daily survey, reporting how MUP was influencing the availability of alcohol in their local environment, influencing consumption patterns and mood.

“I went to the shop for a bottle of frosty and they have stopped selling it coz of the price rise so I'm pissed off”.

Another key factor was family and social support, both in terms of emotional support, but also practical help in managing situations where alcohol is available.

“I've got a strong support. I'm lucky, I've got a strong family that support me, and don't turn their backs on me ...One of the family who didn’t know …actually had put a drink down in front of me. My sister quickly got it out the way.”


The findings of this study give greater insight into the variety of social and psychological processes which may contribute to changes in alcohol consumption at the individual level, and thus the change processes potentially underpinning population level change following MUP implementation. Other projects in the MUP evaluation portfolio will assess the effect of MUP on consumption and harm at the population level.

The study supports understanding the processes through which MUP may have its effect on population consumption, identify possible mechanisms that lead to some heavy drinkers being less affected by the policy, and suggests possible avenues for further intervention approaches to reduce alcohol harm.