Dr. M. Young?Variation in Mortality from Cancer. 205 VARIATION IN THE MORTALITY FROM CANCER AMONGST PERSONS IN THE DIFFERENT DIS- TRICTS OF GLASGOW AND ITS RELATIONSHIP TO SOCIAL STATUS. By MATTHEW YOUNG, M.D., Statistical Department, National Institute for Medical Research. The Medical Officer of Health for the city of Glasgow, in his annual report for the year 1924 issued in August, 1925, states, in a brief reference to the varying incidence of cancer in the municipal wards of the city, that it may be observed that the death-rate from cancer during the year was 1,748 per million in Blythswood, 1,659 in Park, 1,571 in Langside, and 1,594 in Camphill, as compared with 598 per million in Maryhill, 625 in Springburn, and 743 in Govan. His comment on these figures is:?"The most obvious contrast here is that the former group of wards may be regarded as mainly residential and the other as artisan, but that without making an intensive study of classification and its age and sex incidence nothing definite can incidence of the disease in various be said regardingo o the classes of the population." The above-mentioned figures, but without the added reservation, were quoted in the London Times in October, 1925, as showing that cancer in Glasgow among the leisured classes is more than twice as prevalent as it is among the wage earners. This is certainly the impression the crude figures would convey, but it is opposed to the more generally accepted view regarding cancer and social position; as, although one or two observers, including Heron (1907),4 Davies (1924),2 and Roger Williams (1908),7 maintain that cancer is most prevalent in people of high social status; most of those who have studied the problem, including Stevenson (1923),6 Brown and Mohan Lai (1914),1 Maynard (1909),5 and Dublin (1924),3 have come to the conclusion that the mortality from malignant disease 206 Dr. M. Young?Variation in the Mortality from Cancer as a whole in the community declines with ascent in the social scale. Heron's conclusion was originally based on the crude mortality-rates from cancer in the metropolitan boroughs of London for the year 1901. In a later paper, however, he examined the statistics for the four years' period 1901-04, making a rough correction for the varying age constitution of the population in the different London Boroughs by cal- culating the cancer death-rates on the populations between the as cancer in both ages of 30 and 70 years, the bulk of the deaths sexes occur in this age interval. Although the co-efficients of correlation he obtains from these data can only be regarded as doubtfully significant, his final conclusion is that the incidence of cancer is most heavy amongst the well-to-do classes. Brown has made a more detailed examination of the cancer data for the metropolitan boroughs of London for the standardised year 1901 and the four years' period 1906-10, using death-rates, and finds that this procedure reduces the correlation obtained by Heron by the use of crude mortality-rates to such of a degree that the co-efficient between the proportion pro- fessional men in the population and the cancer death-rate becomes doubtfully significant and that between the death-rate and the proportion of domestic servants in private families quite insignificant, as it is less than its probable error. From 1911 onwards the deaths recorded as occurring in the different districts in the annual reports of the Registrar-General have been adjusted where necessary by the .transfer of deaths to the districts to which they belonged. This is of special importance in cancer, as many cases are transferred to hospital for treatment and may die away from their proper districts. For the decennium 1911-20, for which cancer statistics in districts are thus more reliable than in earlier years, correlation co-efficients have been calculated between the standardised death-rates from cancer in males, females, and persons aged in the of London 25 years and upwards metropolitan boroughs and three indices of the general social status of the residents in these boroughs, namely, the number of rooms per person, the number of domestic servants per 100 private families, and the proportion of professional men. The co-efficients are all excess negative, suggesting a direct association between an amongst Persons in the different Districts of Glasgow. 207 of cancer and lower social status, but they are all so small in comparison with their probable errors that no significance can be attached to them. They thus support the inferences drawn by Brown from the data in previous years. Brown also finds a significant negative correlation between the standardised death-rates from cancer in twenty-six divisions of the city of Hamburg for the period 1906-12 and the average income of the inhabitants therein. This result, he states, serves to strengthen the general conclusion that cancer is not more, but less fatal among the well-to-do classes. Stevenson's conclusion is that, generally speaking, there seems to be evidence of a moderate increase of cancer mortality down the social scale, an opinion which is based on the mortality data for cancer amongst males in England and Wales during the three years' period 1910-12. In view of the difference of opinion that still exists regarding the influence of social status on the incidence of cancer, it seemed desirable to ascertain if the cancer statistics for the city of Glasgow in other years supported the general inference that is likely to be drawn from the mortality-rates for the disease in the municipal wards for the year 1924. Unfortunately, the statistics relating to this disease that have been published and made available for Glasgow are not very suitable for such an investigation. No annual totals of deaths from cancer in the different wards of the city have been published for the years subsequent to 1913, and the sexes are not tabulated separately for the earlier years, where such figures are given. In an attempt to make the best use possible of the data that are available, the standardised death-rates from cancer amongst persons aged 25 years and upwards for the four years' period 1910-13, were calculated by the indirect method, i.e., by apply- ing the death-rates from cancer at the several ages for Glasgow as a whole to the populations at the corresponding ages in the respective wards and obtaining factors of correction for the crude mortality-rates. The cancer death-rates in the several age groups in the city of Glasgow for the two years 1911-12 were first applied to the populations at the corresponding ages in the municipal wards, but the standardised death-rates were re-estimated by using the deaths from cancer and the 208 Dr. M. Young?Variation in the Mortality from Cancer populations at the different ages that are tabulated by the Registrar-General for Scotland in his annual reports for the four years 1910, 1911, 1912, and 1913 for Glasgow as a whole, after making such an adjustment of the figures as appeared necessary. The standardised death-rates from cancer in the respective wards derived in this way showed little variation from those already determined. As definite fluctuations in the number of deaths from cancer in the different districts occurred from year to year, four years' statistics were taken to obtain more reliable averages. The figures for the municipal wards that were incorporated in the city at the extension of its boundaries in 1912 were only available for the year 1913; these wards are consequently not included in the analysis. The choice of appropriate measures of the general social status of the residents in the different wards presented some difficulty and was restricted by the kind of information available. There are no particulars for these districts regard- ing measures of social status that are sometimes used, such as the proportion of professional men in the community or the proportion of domestic servants in private families. Certain details exist, however, relating to the distribution of the population residing in the several wards in houses of different size, and the first two of the three measures of social status that have been selected are based on these data and are intimately related to one another. These measures of social condition in the several municipal wards are:? 1. The.average number of persons per room. 2. The percentage of the total population residing in three or more apartment houses. 3. The infantile mortality-rate. They can only be regarded as approximate criteria of social status, but, in general, it may be said that descent in social status is accompanied by increasing density of population and a smaller proportion of the population living in three or more apartment houses. It is also to some extent coincident with a general increase in the infantile mortality-rate. The standardised death-rates from cancer for the four years' period 1910-13, the values of the three selected indices of social status, and the numbers of deaths from cancer in the amongst Persons in the different Districts of Glasgow. 209 corresponding municipal wards are shown in Table I. Blyths- wood Ward, as in 1924, shows the highest death-rate but it has a relatively small population and the number of deaths from TABLE I.-tSHOWING THE STANDARDISED DEATH-RATES FROM CANCER PER 1,000 AMONGST PERSONS AGED 25 YEARS* AND UPWARDS FOR THE FOUR YEARS PERIOD 1910-13, THE AYERAGE NUMBER OF PERSONS PER ROOM, THE PER- CENTAGE OF THE POPULATION RESIDING IN THREE OR MORE APARTMENT HOUSES, AND THE AVERAGE NUMBER OF CANCER DEATHS PER ANNUM IN THE SEVERAL MUNICIPAL WARDS OF THE CITY OF GLASGOW.