This comprehensive review found that financial incentives were effective in changing individual health behaviours in the short term but not, in the few studies to look at longer term effects, beyond 18 months. Improvements stopped soon after the incentive was removed, though lasted a little longer for smoking cessation.
Of the 34 studies included in this review most related to smoking, healthy eating and/or physical activity; no studies relating to alcohol consumption were found. Research was of reasonable quality and, although most studies took place in the US, findings are relevant to the UK.
The effectiveness of incentives was found not to be influenced by their monetary value or the likelihood of receiving them. There was the suggestion that it may be influenced by the deprivation level of participants. This may help us to understand how and why financial incentives work. Future studies should include longer follow-up.
Why was this study needed?
Chronic diseases such as cardiovascular disease, diabetes, cancer and chronic respiratory diseases contribute to over half of preventable premature deaths globally. A lot of attention and resource has been invested into preventing and treating these diseases. These include interventions to help individuals to change behaviours, such as stopping smoking and increasing physical activity, which reduce their risk of developing chronic disease. Incentives can sometimes be financial.
Evidence shows that financial incentives can be effective in changing health-related behaviour in the short term. But it is unclear how long the changes in behaviour last and whether they persist after the incentive is removed.
This review set out to investigate the effectiveness of financial incentives to change a range of health behaviours. It looked at whether effectiveness was affected by the behaviour targeted, the value of the incentive, the likelihood of receiving the incentive, and the deprivation level of the recipients.
What did this study do?
This systematic review identified randomised controlled trials of financial behaviour change interventions with at least 6 months’ follow-up. Most included studies were based in the US and conducted in the workplace, community or medical settings. Of the 34 studies included in this review most related to smoking (19 studies), indicators of healthy eating and/or physical activity, such as body weight (15 studies), and physical activity alone (two studies). No studies directly measured healthy eating – such as via food diaries – or alcohol consumption. Financial incentives ranged from 3 weeks to 18 months and most were offered alongside other behaviour change components, such as counselling or brochures. The comparison groups received the same interventions without financial incentives.
The review searched a wide range of sources and included appropriate quality assurance measures to assess bias in the included studies. Where possible, results from similar studies were pooled together as meta-analyses.
What did it find?
- 39 studies were included in the review and 34 of these, including 10,585 adults, were included in the meta-analyses.
- Overall, financial incentives increased the number of people achieving behaviour change targets at 6 months (OR 1.70, 95% CI 1.42 to 2.02, 33 studies), 6 12 months (OR 1.59, 95% CI 1.21 to 2.08, 28 studies) and 12 18 months (OR 1.53, 95% CI 1.05 to 2.23, 13 studies) after the start of the intervention. However, there was no evidence they were effective after 18 months, although this was based on just five studies.
- Behaviour changes were sustained for up to 2 3 months after the incentive was removed (OR 2.11, 95% CI 1.21 to 3.67, 11 studies) but not longer.
- Interventions targeting smoking cessation were most effective. They worked at all time-points up to 18 months, and up to 3 months after stopping the intervention.
- Those targeting healthy eating and/or physical activity indicators were only effective up to 12 months, and not after stopping. Overall, the effect of the financial incentives for all health behaviours lessened over time.
- The effectiveness of financial incentives was not affected by the value of the incentive or the certainty of receiving it. Financial incentives were more effective in participants with high levels of deprivation compared with less deprived participants at 6 12 months (OR 2.17, 95% CI 1.22 to 3.85), but this was only seen at this single time-point.
What does current guidance say on this issue?
NICE produced a public health guideline on principles for effective behaviour change in 2007. More detailed recommendations for behaviour change interventions targeted at individuals were published in 2014. These guidelines do not make direct recommendations regarding financial incentives, but state that any incentives used must be tailored to the target group to maximise their impact.
What are the implications?
This systematic review indicates that financial incentives can improve short-term behaviour change, but improvements haven’t been demonstrated in the longer term (over 18 months). This might be because they don’t work, or simply that only a few studies have looked at effectiveness over a longer time frame. Studies assessing financial incentives over the longer term are needed to plug and clarify this evidence gap.
Where possible, commissioners should purchase interventions that have demonstrated long term improvements in outcomes. This review suggests financial incentives are currently only able to demonstrate short-term improvements in a select number of health behaviours. The finding that financial incentives appeared more effective, albeit only at a single time-point, in deprived areas, suggests that they may have a place in reducing health inequalities.
Future studies should include cost-effectiveness analyses to ensure financial incentives are affordable and sustainable if implemented. The authors suggest that, given the lack of sustained effects, those planning services should consider individual financial incentives in the context of wider policies at a population or community level to promote and sustain healthy lifestyles.
Mantzari E, Vogt F, Shemilt I et al. Personal financial incentives for changing habitual health-related behaviors: A systematic review and meta-analysis. Prev Med 2015;75:75-85.
Ierfino D, Mantzari E, Hirst J, et al. Financial incentives for smoking cessation in pregnancy: a single-arm intervention study assessing cessation and gaming. Addiction. 2015;110(4):680-8
NICE. Behaviour change: the principles for effective interventions. PH7. London: National Institute for Health and Care Excellence; 2007
NICE. Behaviour change: individual approaches. PH49. London: National Institute for Health and Care Excellence; 2014
Tappin D, Bauld L, Purves D, et al. Financial incentives for smoking cessation in pregnancy: randomised controlled trial. BMJ. 2015 Jan 27;350:h134
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