The promise of behavioural economics is that small, cost-effective changes can have a big impact on behaviour. This could have been written for our project with ColaLife, which focuses on a small but potentially life-saving issue: Getting parents to give sick children a full course of zinc tablets.

This post shares our journey to date and challenges non-profits to pay attention to the behavioural design factors which can make or break their outcomes.

The backstory:

ColaLife is an independent charity inspired by the insight that ‘you can buy a Coca-Cola virtually anywhere in developing countries, but in these same places 1 in 9 children die before their 5th birthday from simple, preventable causes like dehydration from diarrhoea’.

Their product, Kit Yamoyo (The Kit of Life), takes advantage of Coca-Cola’s supply chain to provide essential medications to remote communities. The award-winning packs, containing Oral Rehydration Salts (ORS) and Zinc tablets, are designed to fit snuggly between coke bottles in a crate for easy transportation.

You can read more about  ColaLife here however this post focuses on one small component of their kit: The blister pack of zinc tablets.

The problem: Only 32% of children are reported to have been given a complete 10-day course of Zinc tablets.

ColaLifeShopkeeperParameters and possibilities

Kit Yamoyo is bought directly from local community stores, so parents clearly value the kit enough to purchase it. However the usage data suggests parents typically only give children zinc tablets for the first few days, stopping and storing the tablets when the diarrhoea stops. Although taking medicine to cure the sick is understood, taking supplements to prevent sickness is far less familiar.

We started by mapping the contextual and cultural factors which might influence a parent’s decision to give their children a full course of tablets. We explored education and attitudes, family structures and daily routines, as well as potential mechanics like point of sale messaging, sms reminders and local education programmes. However such initiatives were prohibited by cost and complexity. It became clear that we should start by maximising existing resources.

Attention turned to the 4cm x 10cm foil blister pack.


The parameters were tight. Tablets came without leaflets or inserts, in a standard pack crawling with pharmaceutical copy. The colour, shape and taste were all fixed, leaving us with the small printed strip of foil to work with. Without scope to educate or persuade, our goal would be to influence behaviour on an automatic, instinctive level.

Behavioural insight and strategy

We began by reviewing the academic literature and commercial research around drug adherence, with a view to identifying transferable insights. A lot of evidence for cognitive biases is derived from experiments inside Western Universities, so we prioritised adherence studies in the developing world, mainly around HIV and malaria. We also considered ethical and cultural aspects carefully, benefiting from close collaboration with ColaLife’s team on the ground.

The evidence that design and messaging factors can increase drug adherence is persuasive. Small variations in drug packaging are known to affect adherence rates by as much as 20% – for instance:

  • Perception of urgency is affected by text size, and further enhanced by embedding the message in a black border
  • There is a cognitive preference for picture-based, rather than text based information, especially with users with low literacy levels
  • Response to colour affects adherence and perception of effectiveness; pink sugars pills seem to work better as a stimulant, whereas blue a sedative
  • Packs with calendar design features support daily compliance, as evidenced by contraceptive pill studies.

We also assessed classic behavioural economics approaches, such as taking a pack of white pills and colouring two blue, then advising people to take all the white pills before the two blue ones – the idea being that people assume that efficacy will be undermined by not completing the course. The concept of ‘chunking’ is similar; splitting a task down into more manageable stages to promote completion, as per online surveys and forms.

We then created a range of new packaging concepts informed by these insights, including aspects like:

Messaging: Adding a short, central instruction to the pack, using an active verb: ‘Take zinc 10 days’. Using a large font and surrounding box to amplify importance.
Design: Introducing arrows from the first to the last tablet to prompt movement around the entire pack. Labelling the final tablet with the number 10 to underline the core message.
Colour Differentiating supplements from other drugs through colour. Using vibrant national colours with positive local associations.

The new blister packs are currently being printed and ColaLife will use controlled trials to assess their effectiveness. If successful the approach will be scaled across Zambia and beyond. We’ll be back with results when we can.

Many thanks to ColaLife founder, Simon Berry, for letting us share the story – and for the photos from their excellent Flickr photostream.