Smokers are never too old to quit the habit but sooner is better, a study has found. University of Hong Kong and Department of Health research has estimated the relative mortality risk among 56,167 patients initially interviewed at 18 health centres for the elderly from July 1998 to December 2000. The study determined the relative risks of mortality between former and current smokers and nonsmokers. 'Although the harms of smoking are well established, it is unclear how they extend into old age in Chinese,' said Lam Tai-hing, chair professor and head of the department of community medicine at the university. The research debunked a widely held misconception among Chinese that for elderly people, it did not matter if they continued smoking, he said. Others feared they would die as soon as they quit. 'What we found is if you continue to smoke then you will die earlier,' said Professor Lam. 'Secondly, old people who quit are going to do better than smokers. This means that we must stop smoking as early as possible.' Men who are former smokers have a 40 per cent excess [over and above the average] risk of dying from all causes of death while smokers have a 75 per cent excess risk of dying from all causes of death compared to non-smokers. For women, the relative risks are 43 per cent [former smokers] and 38 per cent [of current smokers] respectively. The study also estimated that excess risks of dying are 59 per cent for those who smoke one to nine cigarettes a day and 84 per cent for those who puff 21 or more. When those who quit smoking were compared with current smokers, the relative risks of mortality for current smokers were 16 per cent from all causes of death, 42 per cent from lung cancer, 31 per cent from cancer and 23 per cent from stroke. The excess risk of dying for women smokers aged 65 to 90 and above was consistently about 50 per cent. The same risk was estimated for men. Professor Lam said there would be a small group of men over 90 who survived despite being smokers, such as Deng Xiaoping . Chan Wai-man, assistant director of health for Family and Elderly Health services, said smoking led to premature lung cancer, heart disease and cardiovascular disease deaths. 'Even when they go into advanced age, the smoking effects will be evident both on mortality and health conditions,' he said. 'These are serious health burdens on the community.' The study appeared in last month's issue of the Journal of the American Geriatrics Society and in the June 2007 issue of Tobacco Control magazine of the British Medical Journal.