Tag Archives: interventions

Should we just give up trying to tackle obesity and smoking through behavioural change?

Studies of behavioural interventions (trying to make people lead more healthy lives) consistently show small effect sizes. An effective smoking intervention would improve quit rates by four per cent1 and a successful weight loss intervention would do well to produce a sustained weight loss of more than five per cent of body weight.2

The really big gains in public health have come not from behavioural change, but from public legislation. Take a few examples:

  1. Forcing tobacco companies to advertise the harms of tobacco.
  2. Raising taxes on alcohol and tobacco.
  3. Seatbelt legislation.

Governments are now considering legislation, regulation or fiscal policies to reduce excessive calorie/sugar consumption. But can we really rely entirely on these measures – should we withdraw funding for research into improved behavioural interventions? I don’t think so for two principal reasons:

  1. There are limits to what can be achieved by public legislation. A classical example was prohibition in America in the 1930s. In the end, it did far more social harm than good. There are limits to how far we can get by coercive means. Very high taxes on tobacco can actually increase consumption by fostering a lucrative black market.3 History repeats itself. Sooner or later, we’re going to have to rely on individual motivation to provide health gains that cannot be achieved by government action alone.4
  2. Many interventions, although of modest effect, can still be highly cost effective. It might be true that a behaviour change can achieve only a four per cent reduction in smoking but the interventions are often relatively inexpensive, and the health effects of a four per cent reduction are impressive when compared to many clinical treatments. In short, we should not be deflected from doing what we can to promote behaviour change on the grounds that the effect sizes are of small magnitude – they are often worth having, i.e. highly cost effective5.

Of course, all this leaves open the important question of how best to achieve behaviour change. There are a large number of psychological and social theories, such as the ‘stages of change’ model6. Incidentally, these theories do not exist in competing or water tight compartments. Many have similar or overlapping elements. One of the theories receiving a lot of current attention is so-called ‘nudge’ theory7,8. I am a very strong supporter of this theory, from both philosophical and psychological points of view, as follows:

  1. Philosophically, this theory makes a lot of sense. It is not illiberal (unlike very high taxation or prohibitions) and recognises human autonomy. In short, it is not coercive. However, it does seek to help people promote their own long-term aims, and overcome short-term impulses. In other words, it seeks to support people when they try to maximise their long-term objectives but succumb to short-term gratification. This philosophical idea is predicated on the notion that there really is a difference between these two things – long-term objectives and short-term gains and that a person can freely choose to place limits on their future options.
  2. This is where modern psychological theory comes in. Traditionally, psychologists have held the view that the acid test of a person’s preferences is their expressed behaviour. If you really want to know what a person thinks about something then their behaviour is the most reliable test – a tenet of behaviourism. However, this does not conform with modern neurophysiology. For instance, it has been found that there are two circuits, one governing desire and the other governing gratification. These are only weakly linked9.

It thus seems both philosophically and psychologically entirely cogent to argue that people have two different kinds of motivation which may be in conflict – their long-term aims and desire for short-term gratification. In short, simply yielding to temptation is not tantamount to expressing an ‘overriding’ or ‘genuine’ preference. No, the brain is modular and can quite easily hold two contradictory beliefs at the same time. In fact, Homer anticipated all this, with the story of Odysseus, who had himself lashed to the mast so that he would not be able to destroy his boat in a desperate lunge to requite his desire for the sirens.

My own University of Birmingham is planning to collaborate with Professor Nick Chater’s group of behavioural psychology, at the Warwick Business School, in taking these ideas forward. We are forging links with the local authorities, both here in Birmingham and in Coventry, so that we can add to the scientific basis for behaviour change.


1. Hughes JR, Keely J, Naud S. Shape of the relapse curve and long-term abstinence among untreated smokers. Addiction.2004;99(1):29-38

2. LaFaive MD, Nesbit T. Higher Cigarette Taxes Create Lucrative, Dangerous Black Market. http://www.mackinac.org/18128 (accessed 26 April 2013).

3. Anderson JW, Konz EC, Frederich RC, Wood CL. Long-term weight-loss maintenance: a meta-analysis of US studies. The American Journal of Clinical Nutrition.2001;74(5):579-584

4. Teixeira PJ, Silva MN, Mata J, Palmeira AL, Markland D. Motivation, self-determination, and long-term weight control. Int J Behav Nutr Phys Act .2012;9(22):1-13

5. Bader P, Boisclair D, Ferrence R. Effects of Tobacco Taxation and Pricing on Smoking Behavior in High Risk Populations: A Knowledge Synthesis. Int. J. Environ. Res. Public Health.2011;(8):4118-4139

6. Prochaska JO, DiClemente CC. Stages and processes of self-change of smoking: Toward an integrative model of change. Journal of Consulting and Clinical Psychology. 1983;51(3):390-395.

7. Thaler R, Sunstein C. Nudge: Improving Decisions About Health, Wealth and Happiness. 1st ed. London. Penguin Books; 2009

8. Nick Chater. Lessons in Nudge Marketing: Wy nudges work… and why they don’t. http://portal.sliderocket.com/ACXHL/Nudge-Marketing-Event-07-07-2011 (accessed 26 April 2013).

9. Bauer M. How to Avoid the Temptations of Immediate Gratification. http://www.scientificamerican.com/article.cfm?id=how-to-avoid-the-temptations-of-immediate-gratification (accessed 23 April 2013).

Public inquiries versus systematic collection of the evidence

The Francis Report1 has had a great influence on British public life – from the Cabinet, through the boardroom and down to the shop floor. The report will be widely quoted for many years to come. The report is 1,782 pages long and contains no fewer than 290 recommendations. But how much can one really learn from such an in-depth analysis of just one site? Contrast the Francis Report with a recent systematic overview of the evidence on quality improvement from the Agency for Healthcare, Research and Quality (AHRQ) in Washington, recently summarised in Annals of Internal Medicine2. This AHRQ study is based on a systematic and intellectually grounded analysis of the entire high quality, world literature. It builds on a similar review conducted on behalf of AHRQ by the Stanford Evidence-based Practice Center over a decade ago. And a very interesting and active decade this has been with an exponential increase in research in the areas of quality and safety of healthcare.

Service delivery interventions to improve quality and safety can be divided, from a methodological point of view, into two classes3. Interventions applied close to the patient, with a specific objective in mind, are ‘targeted interventions.’ Interventions applied more upstream of the patient, with multiple objectives in mind are called ‘generic interventions.’ Generic interventions have much broader or diffuse effects on quality. An example of a targeted intervention is the use of ultrasound to guide the placement of intravenous cannulae. Examples of generic interventions include improving the nurse-to-patient ratio or changing the human resources policy.

Targeted interventions are much easier to study – for example they are much more amenable to evaluation through randomised trials. The AHRQ report shows that a number of targeted interventions are effective, including use of peroperative checklists, outlawing use of hazardous abbreviations, medication reconciliation and various types of guideline such as those concerned with ventilator-associated pneumonia, prolonged use of urinary catheters and thromboembolism prophylaxis.

Generic interventions with diffuse effects, are more difficult to study than targeted interventions. Nevertheless, a compelling case for or against generic interventions can often be built systematically by triangulating various sorts of evidence between and within studies.3 It is in this way, for example, that the authors of the overview conclude that improving the nurse-patient ratio leads to better outcomes (including hospital mortality). The report also produces reasonably convincing evidence in favour of rapid response teams, which can be called out from the intensive care unit to attend patients who are deteriorating on the wards. There is very strong evidence for simulation training, especially for complicated technical procedures, but the case for specific team training (as opposed to training in teams) was somewhat less convincing. There is evidence that surgical ‘score cards’ – that is to say a system where surgeons collect detailed data on their cases – leads to improved care when this is owned by the surgical societies and where individual hospitals are put in charge of improvement efforts. This result would seem to vindicate my recent post on how the outcomes of surgical procedures should influence practice. One ‘old chestnut’ is a question of top down cultural change. The evidence that top down cultural change can be produced through ‘heroic’ leadership is extremely unconvincing. A dispersed model of leadership, combined with bottom up specific improvement practices, seems to be the way to go. The report does not treat safety interventions as a black box, but seeks to understand what makes an intervention work or fail. For instance, rapid response teams are dependent on both good monitoring of patients’ conditions on the ward (the afferent arm) and a rapid, efficient response (the efferent arm). Many guidelines, such as checklists, will merely elicit ritualistic displays of compliance unless practitioners have first been convinced of their rationale.

The above are just a small sample of the extensive evidence in the overview. It is a rich source of high quality evidence, based, wherever possible, on comparative studies. It should be essential reading for clinicians and health service managers.

1. Francis R. Report of the Mid Staffordshire NHS Foundation Trust Public Inquiry. Available from http://www.midstaffspublicinquiry.com/report. Accessed 14 March 2013.

2. Shekelle PG, Pronovost PJ, Wachter RM, Taylor SL, Dy SM, Foy R, Hempel S, McDonald KM, Ovretveit J, Rubenstein LV, Adams AS, Angood PB, Bates DW, Bickman L, Carayon P, Donaldson L, Duan N, Farley DO, Greenhalgh T, Haughom J, Lake ET, Lilford R, Lohr KN, Meyer GS, Miller MR, Neuhauser DV, Ryan G, Saint S, Shojania KG, Shortell SM, Stevens DP, Walshe K.. Advancing the Science of Patient Safety. Ann Intern Med.2011;154(10):693-696

3. Lilford RJ, Chilton PJ, Hemming K, Girling AJ, Taylor CA, Barach P. Evaluating policy and service interventions: framework to guide selection and interpretation of study end points. BMJ 2010; 341 doi: http://dx.doi.org/10.1136/bmj.