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literary & historical

An Irish statistician’s analysis of the national tuberculosis problem - Robert Charles Geary (1896-1983)

An Irish statistician’s analysis of the national tuberculosis problem — Robert Charles Geary (1896-1983) CS Breathnach, JB Moynihan Department of Human Anatomy and Physiology, University College Dublin, Ireland

Introduction Tuberculosis claims two major innovations in medical statistics. Pierre-Charles-Alexandre Louis (1787-1872) is rightly credited with introducing the ‘Numerical Method’ in his approach to phthisis in Recherches anatomico-pathologiques sur la phthisie pulmonaire (1825).1 And randomised, controlled trials, specifically designed by Austin Bradford Hill (1897-1991), were first conducted in assessment of revolutionary anti-tuberculosis chemotherapy.2 It is fitting, therefore, that the contributions of an Irish statistician, Robert Charles Geary (1896-1983), should not be forgotten.

Curriculum vitae Robert Geary was born in Drumcondra, Dublin, on 11 April 1896, the son of Edmond and Jennie O’Sullivan Geary, migrants from Cork and Kerry respectively. His father had returned from the Customs Service in Gravesend to the General Registrar’s Office in Charlemont House (now the Municipal Gallery) where he was responsible not only for vital statistics, but also censuses of population. Geary attended the Model Training School of the Board of Agriculture in Glasnevin and O’Connell School and spent five years in University College Dublin (19131918) before setting off for the Sorbonne (1919-1921) armed with a Travelling Studentship awarded on his MSc (Honours) in Mathematics (1917) (see Figure 1). Though he was appointed lecturer in mathematics at University College Southampton in 1922, the College released him to take up an appointment as statistician in the Department of Industry and Commerce in the fledgling state in Dublin in 1923.3 John Hooper, head of the Statistics Branch, had written to the Secretary of the Department of Industry and Commerce, George Campbell, in November 1922 when Geary joined the Civil Service: I think you should warn him that, if he is to do your work in the manner you will expect, he will have little energy left for any ambitious research in higher mathematics … he is anxious to make a name for himself. His ordinary work will of course be much more prosaic but he will find it interesting.4 For Geary, mathematics was the ‘art of arts’, poetry unalloyed, and a potential theoretical recourse to error elimination from the mathematical expression of physical laws.3 While he was working on his 1943 paper on ‘Inherent relations between random variables’, he read in the Dictionary of National Biography that Robert Boyle’s (1627-1691) famous law was but loosely Irish Journal of Medical Science • Volume 172 • Number 3

demonstrated. From this, I hoped to find in Boyle’s observations a striking application of a statistical theory of error elimination. On reference to the original paper this hope was not realised, for the reason that Boyle’s observations were so accurate and so conclusive as to render error elimination a work almost of supererogation … The words italicised above do less than justice to the work of a great man of science.5 Boyle’s law could no longer be dismissed as an ‘approximately true principle’, a conclusion recently confirmed graphically by John B West.6 In August 1946, Geary was invited by Richard Stone (19131991) to spend a year in Cambridge University in the Department of Applied Economics. After helping to establish the Stone-Geary Utility Function, he returned to Dublin and, in 1949, was appointed Director of the Central Statistics Office within the Department of An Taoiseach. When he retired in 1957 the United Nations availed of his expertise and he served in New York and in the Food and Agricultural Organisation’s Office in Rome. From 1960 to 1966 he was director of the Economic Research Institute in Dublin and subsequently was consultant to the Economic and Social Research Institute. He died on 8 February 1983.3

Phthisiologia In 1930, Geary reported the outstanding statistical study of the mortality from tuberculosis in Ireland. For the fourth year in succession declines had been recorded, but there were 128 deaths per 100,000 in 1929 in Saorstát Éireann. The rate in 1929 was 6.6% less than the rate in 1928, and 53.7% less than the most recent peak in 1904. By comparison with international rates, as revealed in the International Health Year Book published by the League of Nations in 1928, the Saorstát was eighth in a list of 24 countries and held a median position in the percentage declines in the years between 1911 and 1927 among 19 countries. And he was encouraged that the improving trend was not related to the magnitude of the problem anywhere. ‘The high position of Germany (41%) in contrast with that of Belgium (25%), Italy (22%) and France (21%)’ was noted succinctly — comment on wartime starvation and the subsequent shattered German economy may well have been superfluous in 1930.7 In Ireland, the rates per 100,000 population for some of the principal causes of death between 1864 and 1928 were summarised in the Annual Report of the Registrar General for 1928. Extracting the particulars for phthisis, Geary remarked 149

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Figure 1. Masters’ class: Roy Geary, seated on Phyllis Ryan’s left, among the first group of MSc graduates of the National University of Ireland in 1917. Reproduced by kind permission of Dr Dorothy McGeeney, whose father, EJ Conway, is on the right of Ms Ryan (Bean Uí Cheallaigh).

that there was an increase until 1902 after which the rates declined more steeply than during the earlier rise. In England and Wales, the rates — well below the Irish rates — had shown a continuous decline. Furthermore ‘in all ... the linearity of the trends (except for the war years) is rather remarkable’. Prices, crop production and the number of milch cows increased from 1896 so that rural prosperity was higher than ever before, Lady Aberdeen’s Women’s National Health Association did sterling propaganda work against the disease, and the Tuberculosis Prevention (Ireland) Act was passed in 1908, but: The analysis in the previous paragraphs suggests (but does not prove) that the decline in the disease in Ireland at the beginning of the century received its first impetus either directly or indirectly from economic causes.7 The cautionary parenthesis is noteworthy. Analysis of ‘time series’ of quinquennial averages between 1866 and 1927 brought out ‘a rather curious periodicity’ in phthisis mortality and prompted him to seek the underlying causes such as weather and economic conditions. However, as workers in this field are aware, it is difficult to devise a single statistic (a function of temperature, rainfall, hours of sun etc.) which represents ‘weather’. Using ‘the most convenient index [of] annual yield of crops’ no significant correlation was found (r=+0.003).7 ‘Workers in this field’ was as far as he got to mentioning Thomas Wrigley Grimshaw (1839-1900), who was registrar general from 1879. Nor did he include Grimshaw’s 1887 map of the prevalence of phthisis in Ireland when he turned to mortality in the various counties. Although Grimshaw submerged the 150

country under isopleths, isotherms and isobars, a line drawn from Derry to Skibbereen divided the poverty-stricken west with little phthisis from the richer east with its phthisical towns. The gradient westwards was also apparent when Geary plotted the mortality rates from consumption published in the 1841 Census, but the geographical distribution of all forms of tuberculosis from 1923 to 1928 highlighted ‘the high rates in the eastern littoral [that] have often been commented upon’ and revealed a heavier ‘homogeneous’ distribution in contiguous counties north and south of the midlands and Connaught (see Figure 2). Twenty years later (third map) the annual average death rates for all forms of tuberculosis in urban and rural areas had fallen, but the homogeneity had been redistributed; the east coast still carried the highest rates while the lowest mortality, with a few exceptions, was in western and northern counties (Republic of Ireland 1935-1950, taken from Deeny 1954; Northern Ireland 1943, 1945, 1947, Registrar General's Annual Reports). Since 1950, in developed countries, morbidity rates have replaced mortality rates as the index of prevalence. When he opened his paper with some international comparisons,7 Geary adverted to the ‘almost incredible’ figures for mortality from phthisis among Irish immigrants in Pennsylvania and New York as reported by Dublin and Baker in 1910.8 The phthisis (i.e. tuberculosis) mortality rate for Irishborn males ‘was three and a half times as great as amongst the native born, and more than twice as high as for any other race stock on the list’.8 In hindsight, a plausible explanation is afforded by the low rural rates seen in the western and northern counties from which the majority of the young emigrants went Irish Journal of Medical Science • Volume 172 • Number 3

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An Irish statistician’s analysis of the national tuberculosis problem - Robert Charles Geary (1896-1983)

Figure 2. Annual mortality rates (1) from consumption in 1840 and (2) from all forms of rural tuberculosis in 192332,7 compared with all forms in rural and urban areas before the advent of chemotherapy circa 1950. Note the declining numbers in spite of broader inclusion and dispersion.

Wexford — the model county? The high mortality from tuberculosis on the east coast focussed attention on Wexford: Whatever is the underlying cause of the high Wexford rate, it is obviously not economic, for Wexford is one of the most prosperous rural communities in the country. Nor is it housing, for as it happens rural housing is far better in Wexford than in any other county — only 13.6% of the rural population are living in dwellings having more than two persons to a room compared with 27.1% for all Saorstát rural districts.7 In his earlier international comparison, he had recognised that between 1911 and 1927 the percentage decline in tuberculosis mortality was lower in Germany than in Belgium, Italy or France. Small wonder that he added his cautionary parenthesis in discussing the declining mortality from the disease in Ireland at the beginning of the century. What was the problem in the ‘sunny southeast?’ As economic and climatic reasons do not appear to explain the high tuberculosis mortality in Wexford, it was thought that the quality of the soil might be a contributory cause. In England certain enquiries have been made into the relationship between subsoil and phthisis; John Brownlee (1865-1927), Director of Statistics at the National Institute of Medical Research in London, found a positive correlation between mortality from ‘young adult’ phthisis (the predominant type in rural Ireland) and areas lying upon boulder clay in Norfolk, Suffolk and Essex.9 In an investigation into the epidemiology of phthisis in Great Britain and Ireland (1918), Brownlee suggested that differences in phthisis death rates by age groups in different localities indicated the presence of two or more distinct types of disease, and ‘inclined to the view that these types correspond with separate types of the infecting bacillus’.9 At variance with Brownlee’s results, Geary found that there was relatively little tuberculosis in young adults where the general level of health Irish Journal of Medical Science • Volume 172 • Number 3

was high in Irish rural areas.7 However, Geary was seduced by Brownlee’s finding that young adult phthisis was likely to occur in areas situated on boulder clay. And ‘Mr T Hallissy, of the Geological Survey, suggested that the famous marl areas of Wexford might furnish a suitable region for investigation’. Geary confined his attention to the eight littoral districts traversed by marl and ‘at a glance’ found a positive correspondence between tuberculosis mortality rates and marl content ... there could be no doubt that the marl has a dominating influence on the mortality from tuberculosis in the [Wexford] littoral’.7 But correlation is not causation, and his linear relationship is not seen in more recent tuberculosis mortality figures (see Figure 3).

Geary tuberculosis statistics Aprox. %ge of area on marl

to America; with little exposure to tubercle bacilli at home, the absence of naturally acquired immunity left them prey to infection in the teeming cities, and in most cases their phthisis was rapidly fatal.

Mortality per 100,000 p.a. Figure 3. The marl hypothesis slain by the dragon of subsequent mortality rates (annual average for 19381950; annual for 1951) which confirm decline but do not show linear relationships.

Housing, occupation and other factors The annual average rates of mortality from all forms of 151

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Table 1. New cases of tuberculosis notified in Republic of Ireland per 100,000 population. After the introduction of tuberculosis allowances in 1947, notification rates increased without discernible increase in death certification rates; accordingly the rates for 1927 and 1947 are approximations Form Respiratory Non-respiratory

1927 365 155

1947 285 87

1952 189 41

1957 116 28

1967 47 14

1977 29 6

Total

510

372

230

144

61

35

Table 2. Death rates from respiratory tuberculosis (per 100,000 of the population) before and after the introduction of antibiotics in 1947 State

1927

1947

1957

1977

Republic of Ireland Northern Ireland England and Wales

146 141 97

95 73 53

20 13 10

3 2 2

tuberculosis in Irish towns between 1906 and 1926 showed a ‘most pronounced relationship with population: the larger the town the more the tuberculosis.’ There was a strong positive correlation between poor housing and mortality in Dublin but outside the capital there was little relationship between overcrowding and infection. Furthermore, there was no correlation between density of population per acre and overcrowding; housing, density of population and tuberculosis ‘are independent phenomena’.7 Analysis of occupational mortality was hindered by sparsity of information; the numbers of (residents) were not tabulated by occupation, so he stressed ‘the necessity for an exhaustive enquiry into occupation mortality.’7 The data within the paper were used by Geary to exemplify ‘the frequency distribution of the quotient of two normal variables’ in his theoretical paper, of which he was so justly proud, in the Journal of the Royal Statistical Society in 1930.3,10 Geary delivered his paper before the Statistical and Social Inquiry Society of Ireland on 19 June 1930. Theobald WT Dillon (1898-1946) spoke on Geary’s paper on the invitation of the president, John Hooper; he would later make his own contribution to analysis of the statistics of tuberculosis in the 1940s;11,12 his views were particularly irksome to government authorities when his brother, James, put the argument in a nutshell in the Dáil. A summary reported in the British Medical Journal on 12 July noted particularly the recommendation of inquiry into occupational mortality.13 Robert J Rowlette [18731944] who seconded the vote of thanks at the June meeting, expressed the hope in The Medical Press, of which he was the Irish editor, on 6 August that Mr Geary will find opportunity in the future to return to such problems as he has dealt with here, for it is on such studies as his that we may hope to lay the foundations of public health policy. Rowlette had reservations about the role of marl soil in Wexford’s high mortality from tuberculosis.14 By contrasting urban and rural rates it was later shown independently that the county, taken as a whole over the ten years 1923 to 1932, had ‘virtually a county borough rate of mortality’.15

Subsequent studies in tuberculosis Tuberculosis featured in Geary’s paper on ‘Statistical Aspects of Mortality in Early Adult Life’ delivered before the joint meeting 152

of the British and Irish Medical Associations in Dublin in 1952. After examining life expectancy, the decline in death rates, and the close relationship between socioeconomic class and mortality, he tabulated the mortality rates per 100,000 population by cause of death for England and Wales, Scotland, Northern Ireland and Ireland (26 counties), comparing 1900, 1938 and 1949.16 Declining tuberculosis rates were recorded in all four regions: The death rates in 1949 for women from respiratory tuberculosis are in all cases greater than for men. The death rates for Ireland are higher than for the other three areas for both men and women; actually the rates are twice as high as for England and Wales. In 1949, the rates were only about one-quarter of what they were in 1900 for men and onethird for women. It is satisfactory to note that between 1949 and 1951 deaths from respiratory tuberculosis in Ireland at all ages have fallen by 22%. Ireland makes an unsatisfactory showing as regards nonrespiratory tuberculosis. The decline since 1900 has been far less than is the case with respiratory tuberculosis and the rate is four times that for Great Britain. In Denmark (with a larger population than Ireland), the actual number of deaths in 1948 from this disease at ages 15-44 was 28; in Ireland it was 260. Non-respiratory tuberculosis generally had their heaviest incidence at ages 15-24. Pulmonary disease, on the other hand, had its highest rate at ages 25-34 in Ireland; this was true for women in all four areas, but only so for men in Ireland.16 To James Deeny’s (1906-1994) famous statistical 1947 paper,17 which called forth independently the exasperation of Patrick J Galvin and Noel Browne (1915-1997), Roy Geary applied statistical measures.18 Browne castigated Deeny for making statements without furnishing factual evidence and for his naivete with regard to pathogenesis, but he reserved his ire for the suggestion of confinement in isolation colonies and his irony for a Chief Medical Adviser to the Minister of Health with a ‘dilettante interest in epidemiology, diagnosis, treatment and after-care of tuberculosis’.19 (The supreme irony, of course, is that within a few short months Browne was that Minister and Deeny eventually took refuge in the National Tuberculosis Survey — and each subsequently spent his life claiming that he alone had defeated tuberculosis in Ireland, even though the decline in mortality was at least equally as rapid in Northern Irish Journal of Medical Science • Volume 172 • Number 3

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An Irish statistician’s analysis of the national tuberculosis problem - Robert Charles Geary (1896-1983)

Ireland and Britain; see Tables 1 and 2.) Galvin claimed that Deeny failed to substantiate his interpretations and that he misquoted Counihan and Dillon’s 1943 paper to bolster his arguments; more tellingly, he concluded by drawing attention to Deeny’s failure to apply Poisson distribution correction to his ‘clumping’ of deaths.20 And that is exactly what Geary (almost certainly unaware of Galvin's letter which was published in the succeeding volume of the journal and so would not have appeared in the index to 1947 contents) did when he published his closing contribution on tuberculosis in 1955.18

6. 7. 8.

Conclusion By the time that Geary quit the subject it seemed that phthisis, ‘the white plague’, was about to be mastered; in Ireland its eradication had replaced its control,21 which had been the concern of physicians at a Royal Academy of Medicine symposium in 1899.22 From its high place in mortality tables as one of the leading causes of death, tuberculosis has declined and is now so low that it has slipped from consciousness in developed countries. But in 1996 more than 3 million people worldwide died of the disease, and Arata Kochi, director of the WHO Global Tuberculosis Programme, reports that that 22 countries now account for 80% of all cases, and predicts that by the year 2020, 70 million more people will die of tuberculosis.23 Combating poverty, raising living standards, reducing overcrowding, razing slums, remove important contributing factors, but the all-important determining factor is inhalation or ingestion of Koch's bacillus, Mycobacterium tuberculosis. Geary set a headline for all those who desired to apply statistical analysis to medico-social problems in Ireland. His work continues to have relevance in relation to the problem of global tuberculosis from which this island is not immune.

9.

10. 11.

12.

13. 14. 15. 16. 17.

Acknowledgements The authors would like to thank Patricia Hamilton, Belfast, Robert Geary’s later successor TP Linehan, Denis Crowley (1904-2000) who identified the Masters in Figure 1, and Brendan Leeson.

18. 19.

References 1. 2.

3.

4.

5.

Louis PCA. Recherches anatomico-physiologiques sur la phthisie. Paris, Gabon 1825. Medical Research Council. Streptomycin treatment of pulmonary tuberculosis. Br Med J 1948; 2: 769-82; 1950; 2: 1074-85; 1953; 1: 551-63. Hill AB. Statistical Methods in Clinical and Preventive Medicine. Edinburgh, Livingstone 1952. Spencer JE. His life and work. In Roy Geary, 1896-1983: Irish Statistician, Ed D Coniffe, Dublin. Economic and Social Research Institute. 1997; 3-78: 79-90. Linehan T. Geary and Official Statistics. In Roy Geary, 1896-1983: Irish Statistician, Ed D Coniffe, Dublin. Economic and Social Research Institute. 1997; 137-51. Geary RC. Accuracy of Boyle’s original observations on the pressure

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20. 21.

22. 23.

and volume of a gas. Nature 1943; 181: 476 citing Inherent relations between random variables. Proc Royal Ir Acad 1942; 47 (A): 63-76. West JB. The original presentation of Boyle’s law. J Applied Physiol 1999; 87: 1543-5. Geary RC. The mortality from tuberculosis in Saorstát Éireann. A statistical study. J Stat Social Inq Soc Ir 1930; 15: 67-103. Dublin LI. Factors in American mortality: a study of death rates in race stocks in New York State, 1910. Ithaca, New York. Cornell University Press. 1916; Dublin LI, Baker GW. The mortality of race stocks in Pennsylvania and New York. J Am Stat Ass 1920, cited by Geary, 1930. Brownlee J. An investigation into the epidemiology of phthisis in Grat Britain and Ireland. London Medical Research Committee HMSO, 1918. Geary RC. The frequency distribution of the quotient of two normal variables. J Royal Stat Soc 1930; 93: 442-6. Counihan J (sic) E, Dillon TWT. Irish tuberculosis death rates. A statistical study of their reliability with some socioeconomic correlations. J Stat Soc Inq Soc Ir 1943; 17: 169-85. (HE Counihan, chest physician, editor, administrator). Dillon TWT. The statistics of tuberculosis. Ir J Med Sci 1942; 111: 221-43; The epidemiology of tuberculosis. J Med Ass Éir 1945; 17: 142-50. Anonymous. Tuberculosis death rates in Irish Free State. Br Med J 1930; 2: 77. Rowlette RJ. Statistics of tuberculosis in Ireland. The Medical Press 1930; 181: 101-2. Smyth LS. A statistical study of public health in county Wexford. Ir J Med Sci 1934; 101: 289-98, 557-62. Geary RC. Statistical aspects of mortality in early adult life. Br Med J 1952; 2: 625-31. Deeny J. The spread of tuberculosis in an Irish town. A study of slow-motion contagion. J Med Ass Éire 1947; 21: 82-94. Tuberculosis in Ireland, Dublin, Medical Research Council of Ireland, 1954. Geary RC. Does contagion exist? A statistical test and an application. Ir J Med Sci 1955; 124: 88-90. Browne NC. The spread of tuberculosis. J Med Ass Éire 1948; 22: 26-7. Galvin PJ. The Deeny survey — a critical analysis. J Med Ass Éire 1948; 22: 22-3. Grimshaw WT. The prevalence of tuberculosis in Ireland and the measures necessary for its control. Transact Royal Acad Med Ir 1899; 17: 530-64. Letters P. A statistical inquiry into the distribution of tuberculosis in Ireland. Transact Royal Acad Med Ir 1899; 17: 565-83. Bradbury J. WHO awareness of countries failing in fight against TB. Lancet 1998; 351: 966.

Correspondence to: Prof CS Breathnach, Department of Physiology, University College, Earlsfort Terrace, Dublin 2. Tel.: 01 706 7456; fax: 01 706 7417.

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