B-4 Formulation competency
Last updated: April 1, 2025
Formulation sounds challenging. It is not. You are formulating every time you try to understand something, be it an app that does not work, your dishwasher that won’t stop, or your friend who suddenly acts out of character. You analyse the situation using available information in a framework that represents a model of the situation. The better your model, the more likely you are to succeed. Someone who understands how apps and computers work will succeed, whereas someone with no idea will fail. The medical diagnostic process ends with a formulation, though not called that. At a minimum, the doctor reaches a differential diagnosis with a plan to refine the diagnosis. Sometimes, the doctor documents their reasoning. Other health professionals refer to clinical reasoning, another way to systematise and justify decisions.
Thus, a formulation explains a situation within a theory (or hypothesis) you consider appropriate. It originated in psychiatry and is widely used in clinical psychiatry and psychology. However, it is only recognised as a part of psychiatric rehabilitation, not more broadly. It should be used in rehabilitation because psychiatry and rehabilitation confront complex, multifactorial problems without a single cause and requiring multiple interventions. Both use the biopsychosocial model of illness to analyse their patients’ concerns. However, I could not find research into formulation outside psychiatry and psychology. The general structure of a rehabilitation formulation is shown below.
Table of Contents
The Competency.
The trainee analyses and documents a patient’s clinical situation using the holistic biopsychosocial framework, identifying the main problems, the factors relevant to their development and management, and the interrelationships between the factors.
Introduction
Healthcare solves problems. Problem-solving requires an accurate appreciation of the issues, their history and influencing factors, any matters that affect prognosis, the goals and expectations of all interested parties, and a theoretical framework to identify all relevant factors and explain their relationships.
Medical problems are traditionally solved using the biomedical model of illness, which assumes a single specific cause within the body and, usually, a single, if complex, treatment to alleviate or remove the cause. This model collects information about bodily dysfunction, such as symptoms, observed changes, and changes detected using technology. The data is analysed using models of the body, mainly anatomy and physiology, to reach a diagnosis. The formulation is typically limited to the disease diagnosis or differential diagnosis; the explanation is rarely given.
Of course, the doctor can explain in detail how the diagnosis was reached and provide much background information on mechanisms, causes, influence of genes, etc. However, this is rarely documented, even in outline.
The rehabilitation and psychiatric diagnostic processes are entirely different. They do not look for a single causative factor. Instead, they seek to understand the many factors causing or affecting the nature of the person’s problems, aiming to plan remedying actions. The holistic biopsychosocial model of illness is the theoretical framework used in both specialities.
The output is a formulation. Other processes, such as clinical reasoning, are used but do not encompass formulation. The two quotations below illustrate the importance of formulation in psychiatry. Rehabilitation problems are just as complicated and surely warrant an equally thorough analysis.
“The psychiatric formulation is the clinician’s compass guiding treatment. It should accurately reflect the patient and their pattern of functioning as well as the precipitants, predisposing and perpetuating factors, and prognosis, while being clear, concise and clinically useful.”
“The psychiatric formulation is an important and necessary skill for all psychiatry residents. Thorough understanding of the formulation helps residents understand a patient’s unique psychopathology, organize a differential diagnosis, and prepare a useful treatment plan.”
Formulation: history
Gareth Owen wrote a fascinating history, “What is formulation in psychiatry?”. As psychiatry was the first healthcare speciality to use the term, this is a history of formulation. He emphasises that a formulation is holistic because it combines the understanding of meaning with that of explanation (causes).
He starts with a crucial quotation:
“When assessing the same patient, two experts may produce two similar summaries, but two different formulations. This is the fundamental difference: a summary is descriptive, whereas a formulation is analytical and evaluative… formulating a case with clarity and precision is probably the most testing yet challenging and crucial part of a psychiatric assessment.”
(The Maudsley Handbook of Practical Psychiatry, 2014)
Adolf Meyer, a Swiss psychiatrist who moved to the United States, started a psychiatry training programme in 1910. He developed a life chart that encompassed biological, psychological, and social facts. In 1977, his ideas evolved into the more formal biopsychosocial model of illness.
Adolf Meyer’s approach lacked specific approaches, so there was no way to organise or prioritise the information. Eventually, ways of organising the information emerged, such as Jonathan Bolton’s “4 P model,” published in 2014. Other versions, including the 3P and 5P models, have emerged. All categorise the data into groups and use three, four, or all five of the words or concepts given below.
Daniel Thompson and colleagues describe the 5P model of the formulation as applied to community treatment teams. The five categories are:
- Predisposing:
Pre-existing factors such as adverse events, other diseases, family situation etc - Precipitating:
An event or change that lead to the present situation; why they came to your attention. - Presenting:
The issues or concerns raised by the person or others. - Protective:
Anything that is or could reduce the severity of the problems. - Perpetuating:
Anything that may prolong the problems or increase the difficulty of resolving or reducing them.
Theories used in the formulation.
Adolf Meyer introduced the idea of trying to understand complex health problems by acquiring a much greater range of data than used in traditional medical diagnosis. However, he did not develop any way to achieve a more complex diagnosis of a person’s problems. [See ‘What is a diagnosis? Part 1’] The 5 P model categorises the data but does not explain how to use the data.
Problem analysis requires a theory to understand the effects of different items. The biopsychosocial model of illness provides a theoretically based framework to organise the information and, to an extent, a theory suggesting how the relationships act. For many patients, the information in the biopsychosocial framework will be sufficient to understand the situation and how it should be approached.
However, adding a second, better theory will provide more insight in many circumstances. For example, psychological, neurophysiological, and sociological theories can help us understand functional illness, which may lead to a more effective management strategy.
Several papers discuss the potential benefits of using other, more detailed theories in psychiatric practice. These theories do not replace the biopsychosocial formulation; they add detail to aspects, just as increasing understanding of neurophysiological or neuropathological factors may improve a formulation in patients with functional disorders or multiple sclerosis.
Adam Brenner considers how increasing awareness and understanding of the many factors influencing behaviour and experience may influence formulation. He discusses the neurobiological aspects of social stress, the influence of stigma, and the need for doctors to know some sociology and anthropology to understand their patients better. This broader range of knowledge is likely to improve management and outcomes, and I emphasise humanities on this site.
Irosh Fernando and colleagues discuss how formulations may differ depending on the theory used in a psychiatric context, where many psychological theories may explain psychologically based illness. The clinician’s theoretical approach often determines the intervention, and they suggest having a series of templates based on different theories so that the psychiatrist or psychologist can recognise which template is most appropriate for a patient.
Their article emphasises how the theory may influence treatment choice, highlighting the importance of using a good (relevant, appropriate) approach. Rehabilitation is based on the biopsychosocial model and does not have competing frameworks. The General Theory of Rehabilitation may suggest new ways to approach challenging problems.
Undertaking a formulation.
I have not found any research on formulation in rehabilitation. The nearest term is clinical reasoning, but a scoping review by Meredith Young and her colleagues suggests that this approach is primarily used to make specific decisions on diagnosis and treatment. Therefore, I will discuss a practical approach based on my practice and the psychiatric literature.
Rehabilitation is broader than psychiatry. Psychiatry is mainly focused on psychiatric disorders, although liaison psychiatry manages psychiatric disorders associated with other disorders. Rehabilitation applies to all health conditions, including psychiatry. Therefore, the formulation must consider a much wider range of factors arising from one or more diseases.
Formulation has two components: analysis and documentation, recording the outcome of the analysis. The document shows the essential factors you have considered and how they explain the situation. The documented analysis should justify the rehabilitation plan, which is typically integrated into the rehabilitation planning process and the documented plan.
The figure below illustrates an outline of the analytic process. I will comment on it.
Formulation starts with the problems present, which might include matters concerning others that the patient does not necessarily recognise or acknowledge. This will include details about what the patient and others report as the main features.
I have separated disease (pathology) from syndromic conditions. Many people are ill and disabled with an identified pathology. Diagnoses such as fibromyalgia, Long Covid, and chronic back pain are undoubtedly disabling and distressing. The diagnosis is based on the patient’s symptoms and signs. The person’s condition is a syndrome: “a group of symptoms which consistently occur together, or a condition characterized by a set of associated symptoms.” [OED]
The next stage uses the psychiatric approach to identify factors related to the patient’s problems. One should review available information, looking for anything explaining why this person presented now and what might prolong or shorten their problems.
The prognosis and potential interventions implicitly affect planning. The danger is that the assumptions used but not made explicit may be inaccurate, and explicit articulation of assumptions reduces this risk. Rehabilitation planning is frequently based on assumptions that may be wrong, and a more structured and explicit approach avoids overlooking potential actions or factors.
One tremendous but hidden benefit of the formulation is making explicit the many implicit assumptions currently overlooked.
Learning formulation competency - studies
The only studies on learning about biopsychosocial formulation concern psychiatric trainees.
Rob Selzer and Steven Ellen have provided a simple learning aid for biopsychosocial formulation for psychiatric trainees. The basis is a simple table with three columns covering biological, psychological, and social factors in three categories: predisposing, precipitating, and protective. The table is inappropriate for rehabilitation, but having a structured record of the main features always helps.
Ahmed Fayad and colleagues refer to identifying these additional factors as the ‘three Ps approach’; unfortunately, they omit protective factors. They found that constructing a formulation using written case vignettes took about four to seven minutes. I suspect that in rehabilitation, creating the formulation may take longer.
David Ross and colleagues report their experience with a training programme for psychiatric rehabilitation. The programme is based on a book. They use written materials and feedback to trainees; their standard is the formulation given by an experienced senior psychiatrist. Sullivan et al. report using seminar and group activities, sharing experiences from clinical practice. They do not provide specific details.
These studies offer little help to rehabilitation trainers or trainees.
Rehabilitation formulation.
I will first consider formulation in complex cases, usually inpatients. The same principles apply in less complicated cases, but the formulation would be much abbreviated.
The key features are to:
- Collect information encompassing the holistic biopsychosocial model of illness
- Document the key features in a structured way to ensure you have considered each domain and can see the essential features.
- The OCCAM is one way for a service to structure the outcome of the assessment.
- Consider how the mosaic of data interrelates to form logical hypotheses on likely aetiological factors.
- Review the initial formulation with all parties, including the patient and family.
- Write it and circulate it, or
- Present it for discussion in a group meeting
- Use the agreed-upon formulation to plan the next steps.
Proportionality is crucial in all healthcare. A ten-minute general practitioner appointment for a child’s earache is less complex than a healthy 50-year-old man with a new-onset headache and possible clumsiness using his right hand. Similarly, in rehabilitation, a person with a recent ulnar nerve palsy is less complex than someone still entirely dependent after a traumatic brain injury.
However, rehabilitation is intrinsically complex. To avoid being misled by a simple issue, one should always collect peripheral information and develop a rudimentary formulation before acting.
The OCCAM
The formulation depends entirely on the holistic biopsychosocial model of illness as the framework for data and analysis. Each domain must be considered rather than assumed to be irrelevant in a specific case; unwarranted assumptions lead to significant mistakes. The best way to achieve this is to collect at least one item from each domain.
One way to ensure the analysis covers all domains of the biopsychosocial model of illness is to use a structured summary of information gained during the assessment. Based on the biopsychosocial model of illness, the Oxford Case Complexity Assessment Measure (OCCAM) provides an aide memoire tailored to rehabilitation and might be a better framework. First, it explicitly includes context, especially the physical context, which is often a vital component of a formulation and treatment plan. However, the physical environment is less relevant to many people with psychiatric illnesses. Second, it covers a range of impairments commonly seen in rehabilitation but not often applicable in psychiatric practice.
The OCCAM was developed as a practical way to measure case complexity in rehabilitation. The INTERMED, first developed in 2001, is a similar measure based on the biopsychosocial model, but only partially. Scoring is much more difficult. Trainees and medical students have used the OCCAM, and it has been found easy to use and helpful.
The OCCAM is not an assessment tool; one must not complete it during a patient’s assessment. Instead, one might glance at a figure, such as the aide memoir below. The primary use is to summarise the information collected in the evaluation. It allows others to familiarise themselves with a patient’s situation quickly. They will not know the patient but become aware of the essential facts about their rehabilitation.
The complexity score only applies to groups of patients, such as when comparing lengths of stay between services or over time. The items are useful in a patient, but the summary scores are only weakly associated with complexity.
The buttons below show:
- The overall measure, with descriptors for each score
- An aide memoire to use while collecting information
- An assessment and formulation summary document (in Word; it can be downloaded)
- A spreadsheet for collecting scores in a group of patients (only downloads).
Conclusion
Formulation of complex situations is essential for developing an effective management strategy. Many rehabilitation problems are complex and benefit from formulation, yet it is a skill rarely taught or practised in rehabilitation. Here, I have reviewed publications from psychiatry to show what it is and how it may be undertaken. The skill can be taught. However, teaching may not be available, and the information here should enable a group of trainees to learn from each other collectively.
As with all other training, the best approach to learning and improving formulation skills is likely to be:
- Discuss rehabilitation formulation with a trainer or other experienced colleague
- Start writing formulations, using a template if preferred, reviewing each one
- Discuss some formulations with others 1:1 or in small groups, gaining and giving feedback and learning how to improve
- Write out a formulation for all complex cases and a proportion of less complicated cases
- Start teaching others; it’s always a good way to learn!
