Professor Francis Douglas Kelly Liddell, known by his colleagues as Doug, died at his home in Wimbledon, near London, on June 5, 2003.
Professor Liddell was educated at the Manchester Grammar School, UK, and won an open scholarship to Trinity College, Cambridge. He studied mathematics and graduated in 1945 with a B.A., progressing to the M.A. in 1947.
With the war still in progress, he was drafted to the Admiralty where he worked as an experimental officer in the design and testing of naval mines. In 1947 he joined the National Coal Board where he was to spend 21 years, first as a Scientific Officer, later as Head of the Technical Section of the Statistics Department, and ultimately as Head of the Medical Statistics Branch in the Medical Service.
In 1969, Professor Liddell was recruited to what was then the Department of Epidemiology and Health in the Faculty of Medicine at McGill by Professor Corbett McDonald. This was to provide the statistical leadership in the Department, and to support a comprehensive research program that Dr McDonald had developed to examine the health effects of asbestos exposure in the chrysotile mines and mills of Quebec. Promoted to full Professor in 1974, he remained a member of the Department until he retired in 1992 as an Emeritus Professor. When the former Institute of Occupational Health and Safety in Mont-Saint -Hilaire was relocated to the Main Campus in 1981 to become the School of Occupational Health, Dr Liddell became an associate member, a link he held until retirement.
During his twenty-three years at McGill, Professor Liddell was a very active member of the Department, especially during the development of higher degree programs in the 1970’s. He carried full teaching loads, provided statistical consulting, and organized “protocol parliaments” for faculty and students. A number of the current faculty were mentored by him in the teaching of courses such as Applications of Statistics, and Research Design. As a member of the University Senate for 6 years, Professor Liddell was also actively involved in the governance of the University and served on many Senate committees. In 1989-90, while the then Chairman was on sabbatical leave, he served as Acting Chairman of what had become the Department of Epidemiology and Biostatistics.
Professor Liddell was also active in his professional associations, first in Britain with the Royal Statistical Society and later in the American Statistical Association. He served on several Grants Committees and Fellowship Review Committees for the Medical Research Council (MRC) of Canada and for the National Health Research and Development Program (NHRDP). He also served on several national and provincial commissions related to the Health and Safety of workers in Canada.
Professor Liddell had a very productive research career. When he retired in 1992, he had authored 71 articles in peer-reviewed journals and in authoritative texts, and he published nine additional papers as Emeritus Professor, the last of these in 2002. In addition, he was responsible for three monographs. In 1991 along with his co-editor, and later companion Dr Klara Miller, he edited a comprehensive text on Mineral Fibres and Health. His research papers fall into two categories. Several important papers were concerned with statistical methods, including a landmark one in the Journal of the Royal Statistical Society in 1977, coauthored with Professor JC McDonald and his student Duncan Thomas, now a Professor of Biostatistics at the University of Southern California. The remainder, the bigger proportion, focused on occupational health in general, and on the epidemiology of exposure to coal, silica and asbestos in particular. In the 1960’s, he made major contributions to the methodology for reading pneumoconiotic changes in chest x-rays. These were adopted by the ILO and are now the standard procedure throughout the world. His work with Professor McDonald and others on the health effects of asbestos is probably the biggest body of research by any one group in this area. Much of it is based on systematic studies of mortality and morbidity in over 30,000 Quebec chrysotile-asbestos miners and millers. This included a cohort of 12,000 men and women born between 1890 and 1920 and followed through 1992; this material has continued to be the subject of several specific studies to this day. The size of these studies and the data processing that they involved boggles the mind when one realizes that until the 1970s they were undertaken with very limited computing facilities.
Some of Professor Liddell’s most important research was undertaken during his last few years at McGill and in London after his retirement. During this period, his analyses led to the publication of six major papers, four co-authored with Professors Corbett and Alison McDonald, bringing together final conclusions on the risks of mortality from Quebec chrysotile, and two papers with Dr Ben Armstrong on the asbestos-tobacco interaction and on the relative carcinogenicity of the various asbestos fibre types.
Professor Liddell set high standards for himself and expected the same of his colleagues. As a statistician of the old school, he insisted first on hand calculations and on simple methods. He did not hesitate to tell students and faculty when their research projects or other writings were unclear or worse. He was a staunch supporter of the Department and of McGill, and attended every graduation ceremony.
Professor Liddell always had a healthy distrust for statistical packages and “canned” routines. However, he knew well and also took advantage of the power of computers. It was amusing to see Doug introduced to electronic spreadsheets. When Quattro Pro first become available, he quickly saw the benefits of all its embedded functions and flexibility. However, he still made sure that, when he entered a two-way array of numbers, the row totals added up to the column totals, i.e., he checked the spreadsheet by hand to be sure that the functions had been programmed correctly! It was fortunate that Doug lived when he did and that computers developed when they did: in his 10 years of retirement he was able to use his laptop to complete the major analyses of the data collected on the cohort of more than 30,000 Quebec asbestos workers described above. This work would have required room-size computers in the early 70’s when Doug started much of this work.
Apart from medical statistics about which he certainly cared, there were two passions in Doug’s life: classical music and rugby football. He was a constant listener with a vast CD library, and attended every concert that he could. Although only a moderate rugby player in his youth, he became a referee of the highest standard, first in the UK, later on in Canada. In retirement, he seldom missed an “International” and became President of his old club in South London. Of some 50 friends at his funeral, only a few were academics, many of the others were from his old club.
Above all, and in every aspect of his life, Douglas Liddell was a scrupulously honest person of rare intellectual integrity. His unwillingness to compromise in matters of principle or to forgive people and actions which he considered unforgivable were often embarrassing, even for those who agreed with him. Despite this rugged exterior he was a warm and loyal friend whose sterling qualities will not be forgotten.
Prepared by James Hanley, Corbett McDonald, and Margaret R. Becklake