Understanding Representation | MPTS Analysis

The Headline Trap

Imagine you read: "Group A accounts for 60% of all tribunal cases!"

This sounds alarming. But is it? That depends entirely on how many people are in Group A to begin with.

Misleading Stat

60%

"Group A is 60% of cases"

Missing Context

75%

"Group A is 75% of the workforce"

Key insight: If Group A makes up 75% of the workforce but only 60% of tribunal cases, they're actually underrepresented in tribunals — the opposite of what the headline implies.

Visualizing the Difference

Let's make this concrete. Here's a workforce of 20 doctors — 15 from Group A (teal) and 5 from Group B (red):

The Workforce (20 doctors total)

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15

Group A (75%)

5

Group B (25%)

Now, let's say 4 doctors face tribunals. Here's Scenario 1 — proportional representation:

Scenario 1: Proportional (what we'd expect by chance)

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Highlighted = facing tribunal

3

Group A in tribunals (75%)

1

Group B in tribunals (25%)

1.0x

Both groups: Fair

Group A has more cases (3 vs 1), but that's expected — there are more of them. Now here's Scenario 2:

Scenario 2: Group B Overrepresented

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Highlighted = facing tribunal

2

Group A in tribunals (50%)

2

Group B in tribunals (50%)

0.67x

Group A: Under

2.0x

Group B: Over

Same number of cases (2 each), very different meaning. Group B has the same absolute count as Group A, but they're only 25% of the workforce — so they're appearing at twice the expected rate.

The Random Person Test

Here's the clearest way to think about it:

If you picked one random person from each group, who is more likely to face a tribunal?

Using Scenario 2 numbers:

Random Person from Group A

👤

2 / 15

= 13.3% chance of tribunal

Random Person from Group B

👤

2 / 5

= 40% chance of tribunal

👤

3x

more likely

→

to face tribunal than

→

👤

A randomly selected person from Group B is 3 times more likely to face a tribunal than a randomly selected person from Group A — even though they have the same number of tribunal cases.

The Formula

We calculate the representation ratio like this:

Representation Ratio = % of tribunal cases % of workforce

Ratio = 1.0 means proportional | >1.0 means overrepresented | <1.0 means underrepresented

Worked Example (Scenario 2)

Group A

Tribunal: 50% (2 of 4 cases)
Workforce: 75% (15 of 20 doctors)

Ratio = 50% ÷ 75% = 0.67x
Underrepresented

Group B

Tribunal: 50% (2 of 4 cases)
Workforce: 25% (5 of 20 doctors)

Ratio = 50% ÷ 25% = 2.0x
Overrepresented (2x)

Real World Application

In our MPTS data, we compare tribunal appearance rates against the GMC workforce baseline — the actual ethnic composition of UK doctors.

For example:

British doctors might be the majority of tribunal cases in absolute numbers, but if they're also the majority of the workforce, they could be proportionally represented or even underrepresented.
A smaller ethnic group might have fewer total cases, but if those cases represent a higher percentage than their workforce share, they're overrepresented.

This is why we show both views: The raw numbers tell you the scale. The representation ratio tells you if there's a disparity worth investigating.

Toggle "Show Over/Under Representation" on the dashboard to see both perspectives.

Important Caveats

Representation ratios reveal patterns, not causes. Overrepresentation could result from:

Actual differences in behavior or practice patterns
Differences in specialties, career stages, or practice settings
Bias in referral, investigation, or adjudication processes
Statistical noise in small samples
Confounding factors we haven't measured

Correlation is not causation. This data identifies disparities that warrant further investigation — it does not prove discrimination or exonerate any group.