Abbreviations in OET Writing: What to Use, What to Avoid, and How to Write Them

Abbreviations are a natural part of clinical writing — healthcare professionals use them constantly in their daily communication, and OET examiners expect to see them in professional letters. The question is not whether to use abbreviations, but which ones, with whom, and how to format them. Using abbreviations incorrectly (wrong format, undefined specialty terms, informal shortcuts) costs marks under Language and Conciseness & Clarity. Using them correctly signals professional register.

For the full Language criterion context, see OET writing criteria.

Which abbreviations are universally accepted in OET letters

The define-on-first-use rule

Any abbreviation that falls outside universal standard should be introduced with the full term in brackets on its first use:

Incorrect: The TOE showed moderate mitral regurgitation. TOE findings were reported to the team.
Correct: The transoesophageal echocardiogram (TOE) showed moderate mitral regurgitation. TOE findings were reported to the team.

The rule applies even if you are writing to a cardiologist — if the abbreviation is specialty-specific rather than pan-clinical, define it. An OET examiner is marking your professional communication skills, not your specialty knowledge.

British clinical punctuation conventions

OET is assessed against Australian and UK clinical English conventions, not American. The key difference that catches many candidates:

No full stops in abbreviations:

• Titles: Dr Hassan / Mr Al-Farsi / Ms Nguyen — not Dr. / Mr.
• Units: 10 mg / 500 mL / 1.5 L — not 10 mg. or 500mL
• Clinical: ECG / IV / BD / TDS — not E.C.G. / I.V. / B.D.

Space between number and unit:

• 10 mg (not 10mg), 500 mL (not 500mL), 120 mmHg (not 120mmHg)

Lower-case drug names in running text:

• “commenced on metformin 500 mg BD” — not “Metformin”

These are not style preferences — they are clinical conventions that signal whether the writer has professional-level clinical English literacy. Getting them wrong consistently costs Language marks.

What not to abbreviate

Some shortenings that appear in clinical notes should not be carried into a letter:

• Slash abbreviations from notes: “↑BP / ↓Hb” — write these out in a letter: “elevated blood pressure and a falling haemoglobin”
• Colloquial clinical shorthand: “Px” (patient), “Dx” (diagnosis), “Tx” (treatment) — these are note-shorthand, not letter register
• Emoji / symbol substitutions: arrows and plus-signs used as abbreviations are note conventions, not letter conventions

Abbreviations and the Conciseness & Clarity criterion

Using standard abbreviations correctly actually helps the Conciseness & Clarity mark — a letter that writes “electrocardiogram” in full three times is longer and slightly less professional than one that uses “ECG” after the first reference. Abbreviations are a legitimate precision tool, not a shortcut to avoid.

The Writing Checker flags non-standard abbreviation use in context. For a full Language-criterion review of how you are using clinical terminology, including abbreviations, submit a letter for professional correction. The Grammar Checker also catches formatting errors in units and titles.