Mortality in relation to alcohol consumption: a prospective study among male British doctors.
Doll R., Peto R., Boreham J., Sutherland I.
BACKGROUND: To relate alcohol consumption patterns to mortality in an elderly population. METHODS: We undertook a 23-year prospective study of 12 000 male British doctors aged 48-78 years in 1978, involving 7000 deaths. Questionnaires about drinking and smoking were completed in 1978 and once again in 1989-91. Mortality analyses are standardized for age, follow-up duration, and smoking, and (during the last decade of the study, 1991-2001) subdivide non-drinkers into never-drinkers and ex-drinkers. RESULTS: In this elderly population, with mean alcohol consumption per drinker of 2 to 3 units per day, the causes of death that are already known to be augmentable by alcohol accounted for only 5% of the deaths (1% liver disease, 2% cancer of the mouth, pharynx, larynx, or oesophagus, and 2% external causes of death) and were significantly elevated only among men consuming >2 units/day. Vascular disease and respiratory disease accounted for more than half of all the deaths and were both significantly less common among current than among non-drinkers; hence, overall mortality was also significantly lower (relative risk, RR 0.81, CI 0.76-0.87, P = 0.001). The non-drinkers, however, include the ex-drinkers, some of whom may have stopped recently because of illness, and during the last decade of the study (1991-2001) overall mortality was significantly higher in the few ex-drinkers who had been current drinkers in 1978 than in the never-drinkers or current drinkers. To avoid bias, these 239 ex-drinkers were considered together with the 6271 current drinkers and compared with the 750 men who had been non-drinkers in both questionnaires. Even so, ischaemic heart disease (RR 0.72, CI 0.58-0.88, P = 0.002), respiratory disease (RR 0.69, CI 0.52-0.92, P = 0.01), and all-cause (RR 0.88, CI 0.79-0.98, P = 0.02) mortality were significantly lower than in the non-drinkers. CONCLUSIONS: Although some of the apparently protective effect of alcohol against disease is artefactual, some of it is real.