INTRODUCTION
When Sir James Mackenzie moved back from London to St Andrews to establish the Institute of Clinical Research in 1919, he was given an opportunity to reflect on his research and explain why a clinical research institute was needed. In his address delivered at the opening of the Institute and in other publications,1,2 Mackenzie outlined the simultaneous importance of clinical observation: building an evidence base for diagnosis, prognosis, and therapeutic advances; and establishing a systematic approach to clinical care. In this Mackenzie Lecture, I hope to draw parallels between these observations of Mackenzie with the ongoing importance of evidence to the clinical care of patients in primary care in the 21st century. My aim is to illustrate why evidence still matters to clinical general practice using examples that address the domains of diagnosis and prognosis, as well as a critical examination of the risks and benefits of drug therapy. Though these examples are contemporary, Mackenzie’s observations in relation to the clinical and methodological issues are prescient and relevant to 21st-century clinical practice.
INTEGRATION WITH PATIENTS’ DECISION MAKING
Mackenzie understood that researchers should be clear in both their research question and the methods they employ to carry out research, saying ‘those engaged in medical research should pause and consider what they are doing … and be certain that their methods are suited to their purpose’. In this observation, Mackenzie showed considerable foresight in relation to the significant methodological and analytical advances in research methods that have occurred since his time.3 Most particularly there has been the establishment of evidence-based medicine (EBM) in the application of clinical epidemiology to patient care.4 These methodological considerations by Mackenzie are the forerunner in relation to the array of study designs that address important clinical domains in relation to aetiological, diagnostic, prognostic, and therapeutic research. …