Commit to Change

Professor Paul Grob


Early in 2010 the South West Thames Faculty of the RCGP and Surrey University set up a Primary Care Research Unit, the main focus of which was to explore what opportunities were presented by the changing NHS in the field of preventative medicine.  The question asked was “How do you persuade people to do what is good for them?” with a special focus on smoking, exercise and lifestyle changes.

The Commit to Change project explores how the levers of change can be applied within the NHS and incorporated into a specially designed website ( and has been based on an original concept by Ian Ayres and Dean Karlan of Yale University (Carrots and Sticks, Ian Ayres. Bantam Books, New York).


The project utilises the power of a commitment contract, peer pressure and an optional financial stake or wager.  The web based programme allows an individual to define a specific personal health goal (I will give up smoking, I will lose 7lbs in weight, I will take more than 5,000 steps a day).  Just by clearly defining such a health goal the likelihood of success more than doubles.

In addition, the user enlists the help of a group of supporters, family, co-workers, friends, for encouragement who are updated regularly via email on the progress and outcomes of the Commitment contract.  This peer pressure has been found to be a very powerful motivating force.  Moreover, if the GP or his staff are included as supporters this greatly encourages the user as well as affording an opportunity to monitor progress at Practice level.  These activities lend themselves to be published on Facebook, Twitter and personalised blogs and thus very much appeal to the younger computer literate patient, the so-called ‘Facebook generation’.  The reported success rate, without supporters, is 45%, with one supporter 52%, but with two or more supporters the reported success rate rises to 60%.

A referee is selected by the user to track progress and verify the accuracy of the reporting programme.  The user may self-report if so desired.  People who have referees are more likely to report success than those who are on their honour – 62% v. 37%.

In addition, as an additional voluntary, but very powerful, motivating stimulus, the user can put down a financial stake on the outcome.  If he is successful his stake is returned, if not it is forfeited to a selected charity.  Thus it may be suggested, for example, that money normally spent on smoking, usually about £30 per week, be wagered during a 10 week stop smoking programme.  This leaves a stake of £300 at the end of the exercise, thus a single additional cigarette could cost the user £300.  This is a powerful financial incentive to succeed with some individuals

As this project does not charge anything for participants, it is a remarkably cost effective intervention.   It must be recognised that this approach does not appeal to everybody, but for its targeted group it seems remarkably effective and creates a high degree of involvement and cooperation especially if a group of friends can embark upon this approach collectively.

Proof of Concept and Evaluation

This approach to behavioural change has been remarkably successful, having started in America in 2007, has now spread to 28 countries worldwide ( and has been well described in numerous articles especially in the financial behavioural and economics field.  To date over $22.6 million have been staked, 285,664 commitments created, over 741,506 workouts completed and over 13 million cigarettes have not been smoked (at October 2015).  In 2002 Prof Dean Karlan working with the Green bank in Mindanao in the Philippines having set up a commitment project for smokers found that this approach improved the quit rate at six months by 30% compared to controls. 

In a Service Review we have been able to evaluate 940 commitment contracts from the UK in which participants were able to choose their own behavioural change goals.  These could vary from the very easy to the extremely difficult.  There was an overall success rate of 72% in the UK (70% for global users) with about 44% of the goals being health related.  Their breakdown was:

  • Exercise regularly - 11.5%
  • Lose weight - 29.3%
  • Maintain weight loss - 0.6%
  • Stop smoking - 1.8%
  • Run a marathon - 0.3%

UK breakdown by gender:

  • Males - 59%
  • Females - 39%

What was particularly interesting was that 28% of users took out at least one additional commitment goal after the first.  Anecdotally, many would try a very simple goal, for example, taking 5,000 steps a day, and then progress to a more complicated challenge like addressing an alcohol or drugs problem. The ingredients of success are available on our website.

Prevention of Relapse

Many health improvement programmes are very effective whilst the motivation is strong. However, relapse is very common once the initial motivation has stopped.  One of the advantages of the Commit to Change project is that, shall we say, an initial weight loss programme is successful and once the desired weight has been achieved the participant takes out a secondary commitment to not regain the weight.  This has been proved to be successful as it keeps the participant ‘mindful’ of the need to persist in positive behavioural change.  The well known American baseball player Curt Schilling in 2007 successfully staked $2 million to keep his weight in.  In addition, many users would utilise a second commitment contract to ensure that the benefits of healthier lifestyles gained by the first contract were not lost by a return to previously unhealthy behaviour.

The progress of the project to date is available on our website.

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