MORTALITY AND SMOKING MDCBRfSH 1455to 20 cigarettes a day) in September, 1951. In another instance, the doctor had described himself as smoking 3j oz. of pipe tobacco a week, but a friend, who signed the death certificate and had known him for 25 years, stated he had previously been one of the heaviest smokers of both cigarrettes and pipe he had ever known. Such factors not only could not produce an exaggeration of the true relationship but must lead to an understatement of it by inflating the mortality among light smokers and reducing the mortality among heavy smokers. The investigation has not, as yet, continued long enough to show whether there is a relationship between smoking and the mortality from any other disease, but from the preliminary figures it would seem unlikely that there is any as close as that observed with lung cancer. The numbers of deaths, however, from some potentially interesting diseases are as yet small (for example, from cancer of the buccal cavity and larynx and from duodenal ulcer). There have, on the other hand, been a large number of deaths attributable to coronary thrombosis. It seems clear that smoking cannot be a major factor in their production, but the steady increase in mortality with the amount of tobacco smoking recorded suggests that there is a subgroup of these cases in which tobacco has a significant adjuvant effect.
SummarAt the end of 1951 some 40,000 men and women on the British Medical Register replied to a simple questionary relating to their smoking habits. On that basis they were divided into non-smokers and three groups of smokers (including ex-smokers) according to the amount they smoked at that time (or when they gave up).The certified causes of death of those men and women who have since died have been supplied by the Registrars-General of the U.K. over the ensuing 29 months. This preliminary report is confined to the deaths among the 24,389 men over the age of 35.Though the numbers of deaths at present available are small the resulting rates reveal a significant and steadily rising mortality from deaths due to cancer of the lung as the amount of tobacco smoked increases. There is also a rise in the mortality from deaths attributed to coronary thrombosis as the amount smoked increases, but the gradient is much less steep than that revealed by cancer of the lung. The other groups of deaths so far analysed reveal no gradient (other forms of cancer, other forms of cardiovascular disease, respiratory diseases, all other causes).The figures for cancer of the lung are in conformity with those found previously in an extensive inquiry into the smoking histories of patients with cancer of the lung and with other diseases.The death rates of doctors here reported are, almost certainly, artificially low. There is evidence that this is due to a reluctance, or inability, of persons suffering from a fatal illness to reply to the questionary. In spite of this defect and the present small numbers of deaths, we thought it necessary, in view of the nature of the results, to lay t...
