Guidance for Modifying the Definition of Diseases

Abstract

Preventing Overdiagnosis Working Group IMPORTANCE No guidelines exist currently for guideline panels and others considering changes to disease definitions. Panels frequently widen disease definitions, increasing the proportion of the population labeled as unwell and potentially causing harm to patients. We set out to develop a checklist of issues, with guidance, for panels to consider prior to modifying a disease definition.OBSERVATIONS We assembled a multidisciplinary, multicontinent working group of 13 members, including members from the Guidelines International Network, Grading of Recommendations Assessment, Development and Evaluation working group, and the World Health Organisation. We used a 5-step process to develop the checklist: (1) a literature review of issues, (2) a draft outline document, (3) a Delphi process of feedback on the list of issues, (4) a 1-day face-to-face meeting, and (5) further refinement of the checklist. The literature review identified 12 potential issues. From these, the group developed an 8-item checklist that consisted of definition changes, number of people affected, trigger, prognostic ability, disease definition precision and accuracy, potential benefits, potential harms, and the balance between potential harms and benefits. The checklist is accompanied by an explanation of each item and the types of evidence to assess each one. We used a panel's recent consideration of a proposed change in the definition of gestational diabetes mellitus (GDM) to illustrate use of the checklist. CONCLUSIONS AND RELEVANCEWe propose that the checklist be piloted and validated by groups developing new guidelines. We anticipate that the use of the checklist will be a first step to guidance and better documentation of definition changes prior to introducing modified disease definitions.

Overdiagnosis in primary care: framing the problem and finding solutions

“…Because broadening of definitions of disease can lead to overdiagnosis, any changes should use a systematic, transparent approach where benefits and harms are explicit, especially when they lead to an increase in the prevalence of disease, and broadening of definitions should require evidence of clinical benefit. International standards for defining disease and altering disease definitions already incorporate these concepts; such standards could be institutionalized by professional societies and guideline developing organizations 103. Primary care providers could minimize overdiagnosis by avoiding unnecessary screening and testing; a more consistent approach to defining disease would facilitate best clinical practice and benefit patients overall.…”

Mapping the drivers of overdiagnosis to potential solutions

“…3-30 Some authors also cite the need for new evidence informed frameworks to be used when disease definitions are changed, 52 with calls for changes to disease terminology and new expert panels that are more widely representative and have reduced or minimal conflicts of interests.…”

Overdiagnosis: what it is and what it isn’t

“…To prevent and minimise overdiagnosis, we need more studies on the natural history of diseases, watchful waiting trials of very early/small or ambiguous abnormalities, studies of the effects of diagnostic language, intervention studies on known drivers of overdiagnosis, and studies of how to involve patients in decisions about diagnostic strategies. And we need to ensure that new disease definitions are based on evidence,13 not financial interests 14…”