Boyd Diagnostic Strategy

Emeritus Professor Graham Boyd was a man ahead of his time and a fundamental influence on my diagnostic approach. Vale Prof.

He wrote a textbook that started with the opening verse a Kipling Poem:

I keep six honest serving-men
(They taught me all I knew);
Their names are What and Why and When
And How and Where and Who.

– Rudyard Kipling

Sadly his book never caught on, but his legacy as a teacher and mentor does. IMHO his approach continues to run rings around more popular alternatives such as the Murtagh PROMPT model.

Here, in his own words, is a summary of the approach. This is from back in the 1980s when holistic care and the bio-psycho-social approach were yet to become a thing.

The Four-Columned Approach to Clinical Diagnosis

One of the real problems in making clinical diagnosis is the amount of clinical information we have to digest, such that it is often difficult to see the wood for the trees. Accordingly, it is often hard to make a diagnosis all-of-a-piece ” by any “inductive ” or other process of reasoning. With experience you will learn to recognize different disease patterns and readily be able to make a clinical diagnosis in those cases. But pattern recognition is fraught with pitfalls because so often, individual cases depart significantly from the classical. Besides pattern recognition requires experience and so is of little value to those in learning. Also, it is often less than fully descriptive, e.g. ‘myocardial infarction’. Because of these factors, the approach here is to handle the clinical information within a small number of separate categories, each largely independent but which, when put together, severally, describe all aspects of the condition or diagnosis. The following are the four categories:

WHERE is the problem?
- ANATOMICAL DIAGNOSIS = the anatomical system involved.
WHAT is the general pathological nature of the condition?
- PATHOLOGICAL DIAGNOSIS = nature of the condition.
HOW does it affect the patient?
- PHYSIOLOGICAL DIAGNOSIS = functional consequences of the condition.
WHY did the patient get it?
- AETIOLOGICAL DIAGNOSIS = background cause.
- Subsumed under this category is also the question of WHO has the condition and why it occurred WHEN it did.
  - The WHO relates to the type of patient concerned in particular to the social and psychological contexts of the presentation.
  - The WHEN aims to focus on its precipitating factors.

The value of the four-column approach is that it allows you to focus down within each category on much less than the total body of information and thereby gives you a much greater chance of reaching the correct conclusion. Each of the categories contributes, and when taken together, they severally describe all the elements of clinical diagnosis. By contrast, when the pattern-recogniser pins some off-the-rack diagnostic label on a patient, it so often lacks one or other of these categories, particularly the Functional and Aetiological ones. Thus we often hear that a patient has had an ‘acute myocardial infarct’ (Anatomical and general Pathological diagnoses), but where is the comment about how this has affected him functionally (did he have secondary heart failure or ventricular dysrhythmias for example?); and what were the long-term factors predisposing to his condition as well as the more recent ones precipitating it (Aetiological diagnosis) – in this case was there preexisting hypertension predisposing to atheroma and some stressful life event precipitating the episode itself?

The present approach allows you to ‘tailor-make’ a diagnosis (Dx) to the individual patient as you go along rather than force him into some pre-conceived diagnostic pigeonhole read about in some textbook.

Implementation of the Boyd Method

The implementation of this diagnostic model is quite simple. Let’s use chest pain as an example.

Where?

Here we think about the anatomical structures present where the pain is, so for chest pain, we think outside to inside and list:

Skin
Subcutaneous Tissue
Muscles
Spine
Ribs and Costal Cartilage
Pleura
- Parietal Pleura
- Visceral Pleura
Lungs
Heart
- Pericardium
- Myocardium
- Endocardium
Oesophagus
Aorta
Vena Cava
Mediastinum
- Thymus
- Lymph Nodes
- Trachea and Bronchi
Nerves

What?

Here we consider what pathological processes that can occur and are informed by the VINDICATED MEN mnemonic.

Vascular
Infection / Inflammation
Neoplasm
Drugs
Iatrogenic / Idiopathic
Congenital / Genetic
Autoimmune / Allergic
Trauma / Tubes
Endocrine
Deficiencies / Excesses / Degenerative
—
Musculoskeletal / Metabolic (OSA, Obesity)
Environmental (Toxins, SNAP, Domestic Abuse)
Neuropsychiatric / NAI (Non-Accidental Injury)

How?

Boyd Diagnostic Strategy

The Four-Columned Approach to Clinical Diagnosis

Implementation of the Boyd Method

Where?

What?

How?

Skin

Subcutaneous Tissue

Muscles

Spine

Ribs and Costal Cartilage

Pleura

Lungs

Heart

Oesophagus

Aorta

Vena Cava

Mediastinum

Nerves

Why?

The Beauty of the Boyd Method

Education debate: clinical diagnostic reasoning

Abstract