Report variability using standard deviation (SD) rather than standard error (SE). Do not use ‘±’ for SD:
110 mmHg (SD 10) not 110 mmHg (SD ±10)
The most appropriate measure of uncertainty is the confidence interval (CI). This gives an indication of how tightly the results from our experimental sample are expected to predict the ‘real’ value in the wider population. In general, the 95% confidence level is used.
If the 95% CI for the difference between 2 values (eg before versus after, treated versus untreated) includes zero (0), the change is not statistically significant (at the P ≤ 0.05 level).
If the relevant terms have not already been defined, data can be presented as follows:
The risk ratio (RR) was 0.14 (95% confidence interval [CI] 0.08 to 0.24)
If the terms have already been defined, use one of the following formats:
MD 1.11 hours (95% CI 0.98 to 1.20)
The risk was not increased (RR 1.02; 95% CI 0.87 to 1.19)
Do not use an en dash to denote a span of values for the CI because this could be confused with a minus sign:
… with a mean value of 4.23 (95% CI –2.13 to 6.33) not (95% CI –2.13–6.33)
For more information on writing about risk, see Writing about risk.
