Zombie statistics: to make progress we need to kill them off for good

Posted on 14/03/2018 by Amy Keegan (WaterAid UK)

Zombie statistics’. Every sector has them. Statistics that, no matter how many times they are disproven or questioned, just won’t die.

A strong statistic is a powerful advocacy tool. A way to communicate with policy makers and supporters to convey the scale of the problem. If it’s correct. However, using statistics that can’t be substantiated damages an organisation’s credibility. 

In the WASH sector we need to take responsibility for questioning and validating every statistic we use.  If a statistic’s source and methodology can’t be traced, it should not be used. If a statistic hasn’t changed in ten years, it should not be used.

At WaterAid and WASHwatch we are committed to ensuring that our statistics are relevant and verifiable, with a robust methodology. Huge data gaps exist in the WASH sector and these need to be addressed; keeping zombie statistics alive in place of real, powerful stats isn’t helping this.

This World Water Day, we’ve dug out the root of one of the WASH sector’s oldest zombie statistics…

 ‘Half of the hospital beds in the world are filled with people suffering from water-related diseases’

It’s powerful. It presents an image of the impact that a lack of WASH access can have. But is it true? Where did it come from?

If you search the internet for water and sanitation statistics this one appears a lot. It’s rarely referenced, and if it is, the reference is sometimes simply ‘UNDP’ or ‘UNEP’, with no date or specific report.

Fact check

When properly referenced, this statistic can be traced to a UNEP/UN HABITAT report from 2010: ‘Sick water: The central role of wastewater management in sustainable development’. The report opens with a joint statement from the executive directors of both organisations stating that ‘over half of the world’s hospitals beds are occupied with people suffering from illnesses linked with contaminated water.’ This statistic is again repeated on page 40 of the report, referencing a UNDP Human Development Report from 2006 ‘Beyond scarcity: power, poverty and the global water crisis.

The report states that ‘At any given time close to half the people in the developing world are suffering from one or more of the main diseases associated with inadequate provision of water and sanitation such as diarrhoea, guinea worm, trachoma and schistosomiasis (figure 1.5) These diseases fill half the hospital beds in developing countries.’

So, in the move from one report to another, the statistic has changed from ‘all hospital beds in the world’ to ‘hospital beds in developing countries’. It has changed from ‘water related diseases’ to ‘one or more of the main diseases associated with inadequate provision of water and sanitation’.

Within the UNDP report it references Figure 1.5 (below). This figure shows that diarrhoea was the second biggest killer of children in 2004.


The figure doesn’t reference other WASH diseases mentioned in the text or refer to where the half of people in the developing world come from, instead referencing children These statistics come from a 2005 WHO report ‘Make every mother and child count’ looking at deaths of children under five.

The statistics of under-five deaths come from a Lancet article produced by the WHO Child Health Epidemiology Reference Group in 2005 ‘WHO estimates of the cause of death in children’, which references statistics gathered from 2000–2003. By this point the data involved are totally different from the quote we began with.

The further you get from the original quote into source material, the more convoluted and warped the information behind it becomes.

To decide whether this statistic is useable, we need to ask the following questions: Are statistics from 2000-2003 still applicable today? Can we separate the people who have these diseases because of a lack of WASH access and those who have them because of other reasons? Can we equate child deaths with adult deaths? Can we equate deaths with illness? Can we equate illness with hospital beds? Was there ever research to validate the statement that ‘Half of the hospital beds in the world are filled with people suffering from water related diseases?’ Has that research been lost along the way? Is this a case of ongoing miscommunication?


The WASH crisis

884 million people around the world don’t have access to clean water close to home. 2.3 billion people don’t have access to a decent toilet. 289,000 children under the age of five die each year from diarrhoea caused by a lack of access to WASH.

We don’t need to use out-of-date, exaggerated or unsubstantiated statistics. The real ones are bad enough.

We have a long way yet to go to achieve the Sustainable Development Goals and reach everyone, everywhere with access to decent WASH. We can only get there if we are being honest and accurate about our progress

Amy Keegan is a Policy Officer for Monitoring and Accountability at WaterAid. She tweets as @amy_keegan