Reforming disease definitions : a new primary care led, people-centred approach

Abstract

Expanding disease definitions are causing more and more previously healthy people to be labelled as diseased, contributing to the problem of overdiagnosis and related overtreatment. Often the specialist guideline panels which expand definitions have close ties to industry and do not investigate the harms of defining more people as sick. Responding to growing calls to address these problems, an international group of leading researchers and clinicians is proposing a new way to set diagnostic thresholds and mark the boundaries of condition definitions, to try to tackle a key driver of overdiagnosis and overtreatment. The group proposes new evidence-informed principles, with new process and new people constituting new multi-disciplinary panels, free from financial conflicts of interest. Image wikimedia.

Conclusion

Developing a framework for this long-term reform and facilitating a global collaboration to enact it will involve proactive and reactive efforts that we hope will drive a cultural shift and a practical change in how diseases are defined. Research teams will continue to quantify estimates of overdiagnosis arising from current disease definitions, informing priorities for action. Actions include the constitution of new panels, with new processes and new people, to review and revise existing definitions. Concurrently, primary care organisations will become more reactive to expansions in definitions seen as increasing the risk of overdiagnosis, such as the controversial 2017 hypertension widening, explicitly rejected by the American Academy of Family Physicians, and other groups, and the rejection of the expanded definition of gestational diabetes by the Royal Australian College of General Practitioners. An international meeting to review progress on our proposal and develop more detailed strategies for change will take place at the December 2019 Preventing Overdiagnosis conference in Sydney

There are important limitations, uncertainties and caveats to note as we propose this ambitious reform of disease definitions, which will provoke opposition from those whose markets are directly threatened.

1. First, we write as a group working across a multitude of influential national and international organisations, but we do not in this instance represent them.
2. Second, our backgrounds and thinking are largely medical, and there is clearly opportunity for this initiative to be informed by evidence, experience and theories outside medicine, including, for example, from philosophy.
3. Third, addressing the problem of expanding disease definitions is but one of many potential solutions to overdiagnosis, and much important work is underway already to try and wind back the harms of too much medicine, safely and fairly, such as calls to action within our associations, creation of new medical curricula, scientific discussion at national and international meetings and new information materials for the public.
4. Fourth, given the novel nature of this proposal, there is not yet a mature evidence-base to support it.
5. Fifth, there is clear synergy between this proposal and the calls for reform of clinical practice guidelines, which has not been explored in this analysis.
6. And finally, we acknowledge moves to expand definitions, to detect and treat people earlier, are often driven by the best of intentions, and we see great merit in identifying those who will benefit from a medical label and subsequent care.

However, notwithstanding the good intentions driving a bad system, the human person can no longer be treated as an ever-expanding marketplace of diseases, benefiting professional and commercial interests while bringing great harm to those unnecessarily diagnosed.