Numbers, units and measurements in OET letters: how to write doses, weights and results consistently
In an OET Nursing letter, write numbers and units clearly and consistently: use figures for doses, results, measurements and ages ('5 mg', '38.2°C', '64 kg'), keep a space between the number and the unit, and copy every value exactly from the case notes. Spell out vague counts in words where it reads naturally ('two children', 'three times'), and never change a unit or round a number.
Why numbers deserve care
Numbers are where small slips have big consequences. "5 mg" and "50 mg" differ by one character. "Twice daily" written as "BD" may be misread by a non-clinical reader. A weight written "64kg" in one place and "64 kilograms" in another looks careless.
Accurate numbers relate to Content (is the information accurate?), and clear, consistent presentation relates to Conciseness & Clarity and the Language criterion. The rule behind everything in this guide: select the numbers the reader needs, then copy each one exactly.
A consistency guide
| Type | Recommended style | Example |
|---|---|---|
| Medicine dose | Figure + space + unit | "metformin 500 mg twice a day" |
| Frequency | Words, not Latin shorthand | "three times a day", "at night", "when required" |
| Weight / height | Figure + unit as in the notes | "64 kg", "158 cm" |
| Temperature | Figure + °C as in the notes | "38.2°C" |
| Blood pressure | Figures with "/" and unit | "150/90 mmHg" |
| Heart rate / breathing rate | Figure + "beats per minute" / "breaths per minute" or as the notes give | "a heart rate of 104 beats per minute" |
| Oxygen saturation | Figure + % | "oxygen saturation of 93% on room air" |
| Fluid volumes | Figure + mL or L as in the notes | "1.5 L per day" |
| Age | Figure | "aged 78" |
| Everyday counts | Words often read better | "two children", "three steps at the front door" |
| Duration | Figure or words, consistently | "for 10 days" / "for two weeks" |
For dates and times, see writing dates and times in an OET letter.
Five rules for accurate numbers
- Never round or convert. If the notes say 37.8°C, do not write "about 38°C". If they say 140 lb, do not convert to kilograms.
- Keep the unit with the number. "Her weight fell from 64 to 59" is unclear; "from 64 kg to 59 kg" is clear.
- Keep a result with its date when it matters. "Her HbA1c was 8.1% on 3 May" is more useful than "8.1%".
- Show change clearly. Use "increased from … to …", "decreased from … to …" or "remained at …".
- Write frequency in words. "BD", "TDS", "QID", "PRN", "nocte" and "mane" belong in notes, not in the letter. See OET writing abbreviations.
Before and after (invented examples)
| Case-note style | Letter style |
|---|---|
| Paracetamol 1g QID PRN | "paracetamol 1 g up to four times a day when required" |
| Wt ↓ 64→59kg over 2/12 | "Her weight has decreased from 64 kg to 59 kg over two months." |
| T 38.4, HR 112, BP 98/60 | "On admission, her temperature was 38.4°C, heart rate 112 beats per minute and blood pressure 98/60 mmHg." |
| Fluid restriction 1.5L/day | "He is on a fluid restriction of 1.5 L per day." |
| 2 x daughters, 1 lives nearby | "She has two daughters, one of whom lives nearby." |
Note that the arrow "↓" and "2/12" (two months) are case-note shorthand and become words in the letter.
Worked example: a results paragraph
Case notes (invented): Mr Kofi Asante, 69. Adm 14 Feb SOB. SpO2 89% RA → 95% on 2L O2. CRP 120 (14/2) → 18 (19/2). Wt 82kg. Amoxicillin 500mg TDS x 7/7, started 14/2.
Letter extract:
Mr Asante, aged 69, was admitted on 14 February with shortness of breath. His oxygen saturation was 89% on room air and improved to 95% with 2 L of oxygen. His CRP fell from 120 on 14 February to 18 on 19 February. He was started on amoxicillin 500 mg three times a day for seven days on 14 February.
The weight is left out because it does not affect this reader's follow-up. Each value keeps its unit and date. ("CRP" is widely used by clinical readers; for a non-clinical reader you would describe it more simply, using the notes' information.)
Common mistakes
- Missing units. "His dose was increased to 10" — 10 what?
- Mixed styles. "5 mg" in one sentence and "five milligrams" in the next.
- Copying shorthand. "x 7/7", "2/52", "↑" and "↓" are not letter language.
- Typing errors in values. Re-read every number against the notes before you finish.
- Listing numbers without meaning. Say what changed: "improved", "remained stable", "increased".
- Including every number. Select first. A list of normal values adds words without helping the reader.
For more on results and medicines, see vital signs and test results in an OET letter and how to write medications in an OET letter.
Practise and check
Practise a timed letter at /writing/, or check a letter you have written to get an estimated grade, a mark for each of the six criteria and line-by-line corrections. medEmu is an independent practice tool for OET Writing for Nursing; its grades are estimates, and it is not affiliated with OET.
Sources
This guide is medEmu's writing advice, not official OET guidance and not clinical advice; all patients, doses and results are invented for practice. The network used for this run could not reach oet.com, so no OET test facts (such as OET's own position on number or unit style) are stated; check oet.com for official guidance. For OET's official Writing information, see oet.com.