An INDEPTH Look at Mortality Data

The INDEPTH network has today released a massive amount of information about cause of death from countries in Africa and Asia. Up until now such information was patchy, limited to single sites and often the underlying data were not available for investigation by other scientists. The head of Population Health at the Wellcome Trust, Jimmy Whitworth, explains why this release is so important and how it will change the way we approach research and policy on child death in low- and middle- income countries.

It is astonishing to find that in the 21st century there are still multitudes of people whose entire lives go officially unnoticed.

In sub-Saharan Africa, it is only in South Africa that there is comprehensive recording of births and deaths. Elsewhere on the continent populations are just estimates based on censuses that happen about every ten years.

Amongst other things, this situation is unsatisfactory for planners and policy makers. It is also a problem for those tasked with organising health systems and services, and those trying to report on the numbers (let alone the causes) of diseases and deaths. As a result most health reports from low- and middle-income countries are based on modelling projections rather than actual events.

One solution to this problem has been to set up long-term Demographic and Health Surveillance Sites (DHSS) where the whole population of a defined area can be observed. Typically survey teams will move from house to house once, or more often, each year recording births, marriages, migration, deaths and collecting health information from the inhabitants.

Dozens of these DHSS exist around the world and they are an invaluable source of information for national policy makers and planners. The value and validity of the information generated can be strengthened by collecting data to a common standard across many sites and comparing and contrasting the findings. For over a decade the Wellcome Trust has supported INDEPTH, a network of DHSS with a secretariat based in Ghana, which has recorded and analysed  cause of death data from sites across Africa and Asia.

Much of this work has been based on the development of computer-based methods to capture and combine information from different reporting systems at individual sites. Data covers a range of common causes of death such as malaria, HIV/AIDS, maternal deaths, communicable disease, and external causes such as accidental death, suicide and murder. One of the important datasets looks at childhood mortality, capturing information on over 28,000 child deaths.

The results show a wide range of infant and child mortality rates across the sites and also show a variety of patterns of causes of deaths. There are some key conclusions that can be drawn from the results.

Malaria is still a major cause of death for children in most of sub-Saharan Africa, especially in West Africa. HIV is a major cause of death of children in South Africa, while external causes, mostly drownings, are common in Bangladesh.

Some countries have several sites reporting in this study, and they often show varied patterns, demonstrating that the findings from one DHSS cannot necessarily be taken as representative of a whole country.

The causes of death were ascribed following a standardised set of questions administered by trained staff to close relatives of the deceased child. This technique, called ‘verbal autopsy’, has been shown to be reliable for identifying many broad causes of death, but it does have its limitations – reflected in the large proportion of ‘indeterminate’ deaths reported at some sites.

In line with Wellcome Trust policy, all of the information, including the individual data records, is being made openly accessible to anybody wishing to study the datasets further. This vast repository of rich information will be invaluable to population scientists, health planners and policy makers, especially those in low- and middle-income countries.

We would like to extend our congratulations to INDEPTH and the scientists at the individual sites are on their tremendous achievements so far.

You can find out more about INDEPTH in this press release and access all the available data via the INDEPTH iShare project website. The journal Global Health Action has just published a special issue which looks at the INDEPTH findings in more detail.

Image credit: INDEPTH network/Peter Byass