2021 Marshall Joffe Methods Award Winner
Malcolm Maclure
“I am a ‘case of crossover,’ oscillating between academe and government, trying to combine the active skepticism of Tom and Iain Chalmers with the skeptical activism of Dr. Bernard Lown, co-founder of International Physicians for Prevention of Nuclear War. While I was an Assistant Professor at Harvard School of Public Health, helping Dr. Lown with a peace project (1986-88), I met another IPPNW activist, cardiologist James Muller, who invited me to help him design what became the Myocardial Infarction Onset Study. Read more
My doctoral work, a case-control study of kidney cancer, had sensitized me to selection bias in control groups. So, for the Onset Study, I agonized over every suggested control group until I hit upon using afternoon heart attacks as controls for morning cases, and vice versa. Gradually I realized cases could be their own controls. Emboldened by teaching a course using Sander Greenland’s Evolution of Epidemiologic Ideas, I named it the case-crossover design, hoping it might be useful to others. After publishing the paper and wearily completing revision #23 of the interview form, I left the Onset Study to Murray Mittleman who solved its logistics challenges and developed theory on control sampling strategies for case-crossover studies.
In 1991, I migrated to promoting trials of policy and programs in British Columbia PharmaCare, inspired by Tom Chalmers’s 40 years of randomizing. That led to a long collaboration with Sebastian Schneeweiss including my continuation as an Adjunct Professor at Harvard until 2016. Drug policy studies led me to meet pharmacoepidemiologists in Odense, Denmark, who were planning case-crossover studies, notably Jesper Hallas with whom I continue to work, including clarifying parallels between case-crossover and symmetry analysis. On leave from PharmaCare, 2002-2006, as Professor at University of Victoria’s School of Health Information Science (thanks to a career award from BC’s Michael Smith Foundation for Health Research), I helped create a BC node in Murray’s Stroke Onset Study. In 2007, SER invited me to run for president, which gave me a podium in 2009 to urge epidemiologists to be leaders against climate change.
Murray’s application of case-crossover methods to study healthcare worker injuries gave me confidence to compete for a Professorship entitled BC Chair in Patient Safety, endowed by the Ministry of Health in the Dept of Anesthesiology, Pharmacology and Therapeutics at UBC. From 2009-2012, my Professorship encompassed my government position as Director of Research and Evidence Development in PharmaCare. In those years, with David Madigan’s FDA-sponsored Working Group on Case Only Designs (2011), I worked out many similarities and several key differences between case-crossover and self-controlled case series designs for drug safety monitoring. In 2012, my initiative in promoting policy-relevant research triggered my involuntary oscillation back to full-time academe (7 staff were fired for taking initiative that new bosses didn’t understand) until the Ministry apologized and rehired me as Research Scholar in Residence (2018-2020) to develop rapid-evaluation with Designed Delays (control groups).
In the interim, with Andy Carson-Stevens, a patient safety activist in Wales, I developed a plan to apply case-crossover methods to routine adverse event reporting in hospitals but our progress has been slow. In 2016, I joined Suzanne Cadarette’s Self-controlled Crossover Observational PharmacoEpidemiology (SCOPE) Group in producing guidance (‘Control Yourself’, in press) and tools (forthcoming) for case-crossover, self-controlled case series and symmetry analyses. Through Will Dixon’s ‘Cloudy with a Chance of Pain’ Study in Manchester UK (2017-19), I have become excited about emerging opportunities for self-controlled analyses of data from smart phones. I see these as platforms for potential n-of-1 studies in diverse domains. Meanwhile I focus on improving quality of quality improvement methods: surgical quality outcome reports and pragmatic trials of audit-and-feedback to family physicians using ‘prescribing portraits’ made by Colin Dormuth’s Pharmacoepidemiology Group in the Therapeutics Initiative at UBC.”