Diagnoses provide clinicians and researchers with a way to classify and communicate sets of signs and symptoms. Often these clusters of symptoms are presumed to have some underlying similarity – either similar causal mechanisms, or response to similar treatments.
However, they reduce the emphasis on individual differences between patients, and can cause clinicians to assume that a similar presentation (or group of signs and symptoms) have the same causes.
A diagnosis is helpful when we talk to each other – making sure we use consistent terms and are talking about the same things. Diagnoses have limitations though:
- They often make assumptions about cause and effect
- They group together similarities rather than identifying what is unique to this person
- They don’t tell us how signs and symptoms are affecting the person we are seeing
In the case of persistent pain, often we don’t know what causes or maintains the experience of pain.
There are many factors contributing to persistent pain and disability including biophysical, psychological and social. This means each individual is unique, and our treatments need to be tailored to suit.
A case formulation refers to developing an individualised explanation of relationships between causal mechanisms and presentations in an individual.
“Case formulation is an experimental, hypothesis-driven procedure in pursuit of a “clinical theory” (the problem formulation) which then acts to guide ongoing therapy” (Bruch & Bond, 1998). The aims of case formulation are to:
- explain the onset and maintenance of a clinical presentation
- form the basis of intervention hypotheses
- tailor treatment to individual needs
This process involves considerable time spent on assessment, because important decisions and interventions are involved that have long-term consequences for the patient.
A case formulation approach is recommended in pain management, because the person we see in a clinic presents with many different factors influencing their life in many different ways – our treatments must appreciate the uniqueness of each individual.
The model of chronic pain used influences the assessment and treatments offered
The biomedical model looks only at biophysical factors in a health condition – and this can be very helpful when the mechanism of the problem is clear (e.g. a broken bone), and the treatment is similarly clear (e.g. immobilize the bone until healing is complete).
In pain, acute or chronic, we have a very different situation – our knowledge of what contributes to the experience of pain, and the disability that develops as a result is still limited. We have to look beyond the biophysical, and include psychological and social factors. The relationship between these various factors, and the decision about which factors are important, is what assessment and discussion with the individual achieves.
The specific factors to include in an assessment are developed from research, but the general domains include
- Physiological response
- Motor behaviours
- Learning history
- Environmental contingencies including family, significant others, litigation, financial, agencies
- Iatrogenic influences including medications, investigations, procedures
The relationship between each of these factors is the subject of both ongoing research, and will differ between individuals – it is this relationship that is the subject of assessment. And that is the subject for another post!