THRESHOLD-BASED GUIDELINES THREATEN PREFERENCE-SENSITIVE DECISION MAKING IN PERSON-CENTRED CARE

Purpose:

   To show that thresholds which divide individuals into diagnostic or therapeutic categories on the basis of a single criterion are a threat to the preference-sensitive decision making essential in person-centred care and fully informed consent.

Method(s):

   Cut-off based classifications are endemic in clinical medicine. Persons are allocated to groups such as ‘high, medium and low risk’ that are likely to differ in the testing and/or treatment experienced, such differentiation being a fundamental purpose of the categorisation. In the extreme case the existence and severity of a disease or condition is defined by a cut-off imposed on a continuum, often a statistical parameter for a population. The classification can even determine an individual's access to the personalised decision support tools characteristic of preference-sensitive decisions in person-centred care (PCC)

   Using bone health as our representative exemplar case, we investigated whether classification on the basis of FRAX assessment of fracture risk can lead to inappropriate management, irrespective of where the cut-offs are placed; testing or treatment that is inappropriate according to the principles of PCC as implemented in a necessarily multi-criterial decision support tool. The possible undesirable consequences include over-or under- diagnosis and/or over- or under- treatment, all of which should be included as criteria. The value of personalised assessment of absolute fracture risk as an important decision input is not in question.

Result(s):

   In a series of interactive examples we show that NOGG guideline classifications and recommendations based on FRAX-assessed probability of fracture (with or without BMD) bear no necessary relationship to the results emerging from integrating a variety of multi-criteria importance weights with the best estimates available for the performance of the options on all criteria.

Conclusion(s):

   The introduction of thresholds can prevent a patient classified in one group (e.g. 'assess') from receiving the care appropriate for them, given their preferences (e.g. 'reassure'). Traffic light triaging is a diversion from the task of explicitly eliciting and processing the person’s preferences and an ethically unacceptable nudge to treat themselves as average for their group or subgroup. If the response to this is that the clinician can deal with this at the point of decision by eliciting the individual's preferences, the pertinent question to ask is 'What is the point or value of introducing the prior categorisation?'