Introduction

The most efficient way to improve health is to use locally available, sustainable, and effective approaches. In the 1970s policy developers tested the concept that public health interventions could be designed around uncommon, beneficial health behaviours that some community members already practised.1 2 This concept—known as positive deviance3 4—was used successfully to improve the nutritional status of children in several settings in the1990s.5^–10 Recently, the approach has also been applied to newborn care, child nutrition, rates of contraception, safe sexual practices, and educational outcomes.11^–13 In this article we describe how the approach works, the evidence that it is effective, and possible future applications.

How does positive deviance work?

Positive deviant behaviour (box) is an uncommon practice that confers advantage to the people who practise it compared with the rest of the community. Such behaviours are likely to be affordable, acceptable, and sustainable because they are already practised by at risk people, they do not conflict with local culture, and they work.15 For example, in Egypt, contrary to custom, parents of poor but well nourished children were found to feed their children a diet that included eggs, beans, and green vegetables. Child nutrition programmes that provided opportunities to parents of malnourished children to follow this and other new behaviours, such as hand washing and hygienic food preparation, improved child growth (figure).

Mother learning new feeding practices at a mother-infant group learning centre in Abo Sidom, Egypt

The positive deviance approach involves partnering with communities to:

• Develop case definitions

• Identify four to six people who have achieved an unexpected good outcome despite high risk

• Interview and observe these …