Researchers are calling for official death registries in all countries around the world to record whether the dead person was a smoker.
It follows new analyses of nearly half a million death records in South Africa which show that the death rate from tobacco is more than twice as great among those of mixed race than in the white population.
South Africa is the first, and so far the only, country to record smoking on death registration forms.
'Death registries around the world should routinely ask whether the dead person was a smoker,' said Professor Sir Richard Peto of the Clinical Trial Service Unit at the University of Oxford, and a member of the international research team. 'This would help assess national death rates from smoking and would help countries discover whether deaths from smoking are increasing or decreasing. There will be hundreds of millions of tobacco deaths this century if current smoking patterns continue.'
The new study, which is the first large-scale analysis of mortality from smoking in any African country, found that in people of mixed ethnic origin, smoking causes one in four of all deaths in middle-aged men and one in six of all deaths in middle-aged women. The findings are published in the medical journal The Lancet.
The black population already accounts for more than half of all deaths from smoking in South Africa, due to its larger size. At present, the death rate from smoking is not yet as high in the black as in the white population, but the researchers warn that this is likely to change if the large numbers of young black adults who now smoke continue to do so. The system of recording smoking on death notification forms will, however, automatically monitor any future changes in the death rate from smoking.
South Africa modified its national death notification form in 1998 to ask a simple yes/no question about whether the dead person had been a smoker five years earlier.
The international team of researchers has now analysed the answers on the death notification forms of nearly half a million adults in South Africa who died during the period 1999–2007.
Lead author Professor Debbie Bradshaw of the South African Medical Research Council said: 'There is already a high death rate from smoking in the mixed-ancestry coloured population of South Africa, and there will be major increases in tobacco-attributed mortality in many other African populations where young adults now smoke, unless there is widespread cessation.'
Professor Freddy Sitas of the New South Wales Cancer Council in Australia is another study author, who in 1994 first proposed including the question about smoking in South African death registries. He added: 'Our results show that in 1999–2007, smoking caused many deaths from cancer and heart disease, but the main way it killed, particularly in the black population, was by increasing mortality from tuberculosis and other lung diseases. All countries have heterogeneous populations, and need to know how disease-specific mortality from smoking varies with cultural background and socio-economic status.'
In an accompanying piece in The Lancet, Professor Lionel Opie of the University of Cape Town, South Africa – who was not involved in the research – says: 'This remarkable article assesses the lethal effects of smoking from the answers to one simple – but key – yes or no question on the South African death registration form: smoker or not, five years before death? This vital question has led to new understanding in South Africa, and could do likewise elsewhere. Even in countries with sophisticated health systems, it should become part of the routine death registration process.'
The study was funded by the South African Medical Research Council, the UK Medical Research Council, Cancer Research UK, the British Heart Foundation, and the New South Wales Cancer Council.