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top decile is only one-fifth of that predicted for a 10% fall inthe population’s mean level.Thus reductions in blood cholesterol can be expected to

extend life and to decrease deaths from CHD, with acompensating increase in deaths from other causes,

including cancers. A reduction in smoking alone would leadto an increase in lifetime CHD deaths with a decrease incancer deaths, whereas a lowering of cholesterol levelswould have the opposite tendency. In combination thesechanges would tend to cancel out, the net effect dependingon the relative size of each change.

Blood pressureThe treatment of hypertension by drugs has only a smallimpact on mortality,4 and the effects on mortality ofreducing blood pressure by other means are not known.Therefore, we did not try to calculate how a policy ofscreening and treatment might affect the pattern of

mortality. If a lowering of the whole blood pressuredistribution were to be accompanied by correspondingchanges in mortality rates, then its effects on the pattern ofdeaths might be similar to those from cholesterol reduction.

Discussion

Our findings relate only to mortality, but it is to be hopedthat the extra years of life achievable by preventive measuresagainst heart disease will also tend to be healthier years oflife. CHD is chronic and the final acute illness is commonlypreceded, perhaps for a decade or more, by minor disabilityfrom shortness of breath or mild angina. The prevalence ofthis morbidity is related to the major coronary risk factors, sothat benefit is to be expected if these factors are controlled.In addition, smoking is the chief cause of chronic airwaysobstruction. Measures which reduce the incidence of majorcardiorespiratory illness should therefore also reduce theyears of disability that may precede it, as well as postponingor preventing the more severe disability that often followsmyocardial infarction.A J-shaped relation of serum cholesterol to total mortality

has been reported in many studies, the excess deaths in menwith low cholesterol being mainly from cancers. This excessis generally a short-term phenomenon,s thought to reflectthe nutritional and metabolic effects of early cancer. Amongthe studies where some long-term association persistedthere was no consistent pattern, and unidentified

confounding factors related to social class may well be theexplanation. For example, in a study from Glasgow,6 theassociation was absent in women and in men it was

significant only for lung cancer. There is no evident

tendency towards an excess of cancers in low-cholesterolpopulations, such as those of Mediterranean countries; norhas the decline in CHD mortality, seen in several countriesin association with falling cholesterol levels, been offset by aparallel increase in cancer deaths. Most pertinent of all, therandomised intervention trials taken as a whole do not

suggest that cholesterol-lowering dietary change is followedby any increase in cancer incidence. Thus the evidence froma range of studies is largely reassuring: lowering serumcholesterol by dietary means does not seem to change theage-specific risks of cancer or other major diseases, at least inthe early years. Long-term monitoring to look for eitherharm or other benefits is nevertheless called for.The application of mortality predictions to real

populations is complicated. The predictions are based onthe assumption of stability, both of exposures and of

age-specific rates. The pattern of mortality will changedifferently during a transitional period, such as now affectsmany countries, in which exposure levels and disease ratesare in a state of flux. If there is then a period of greaterstability we might expect a postponement of cardiovasculardeaths, with no great change in the total number of suchdeaths but an extension of life and of symptom-free years.These predictions are based on a study of middle-aged

men. Preventive measures started earlier in life might have abigger impact. To the extent that preventive measuressucceed in reducing the lifetime probability of death fromcardiovascular disease, then there will be a compensatoryincrease in the probability of death from other causes.

REFERENCES1. Reid DD, Brett GZ, Hamilton PJS, Jarrett RJ, Keen H, Rose G.

Cardiorespiratory disease and diabetes among middle-aged male civilservants: a study of screening and intervention. Lancet 1974; i: 469-73.

2. Rose G, Shipley MJ. Plasma lipids and mortality: a source of error. Lancet1980; i: 523-26.

3. Rose G. The strategy of prevention: lessons from cardiovascular disease.Br Med J 1981; 282: 1847-51.

4. Medical Research Council Working Party. Stroke and coronary heartdisease in mild hypertension: risk factors and the value of treatment.Br Med J 1988; 296: 1565-70.

5. International Collaborative Group. Circulating cholesterol level and riskof death from cancer in men aged 40 to 69 years. JAMA 1982; 248:2853-59.

6. Isles CG, Hole DJ, Gillis CR, Hawthorne VM, Lever AF. Plasmacholesterol, coronary heart disease, and cancer in the Renfrew andPaisley survey. Br Med J 1989; 298: 920-24.

Then as Now

The health of Russia

Before proceeding to the consideration of factory legislation inRussia, a reference may be made to a matter of almost equalimportance to the extreme scarcity of doctors already noticed-namely, the absence of medicine and the relatively small number ofapothecaries’ shops. The chief cause of the former fact is the highprice of drugs, especially for such a poor country as Russia. Itsserious bearing may be judged from the fact that intermittent feveraffects every year millions of people in the south and south-east,especially in the Caucasus. The most efficient remedy known is, ofcourse, quinine; but so expensive is the drug that even militaryhospitals are insufficiently supplied. How then, should Cossacks,Kirgiz, &c., be provided? Under a system of monopoly. Thenumber of apothecaries’ shops is in some governmentsastonishingly small; in Archangel, with an area nearly three timesthat of the United Kingdom and a population of a third of a million,there were three. In 1887 there were in all 2670 shops, doingbusiness to the extent of about two millions sterling to a populationof about 110 millions.Workmen and factories have but lately occupied the attention of

Government. The Industrial Code of 1775 and the statute of 1806exist little more than on paper ... The projected scheme for paidmechanics never ripened into law. Accidents in factories, mines,&c., are still regarded from the ancient standpoint, and settled by areference to the will of God. But the results of occasional accidentsare insignificant compared with the continuous influence of

insanitary and unregulated industries, especially where the latterare, in their nature, injurious to the workmen. In the presence ofgrave evils, the question of who should be entrusted with the newduties of inspection excites more interest than the evils themselves.Shall it be the zemstvo, or local authority, a representative chosen bythe workmen concerned, or the police?

(From The Lancet of 25 January 1890)