How to make a Table 1
- Paste one row per participant from Excel, SPSS or Stata, or drop an .xlsx or CSV file. The example shows the format.
- Choose the group column (arm, exposure, cohort), or none for a single column.
- Check each variable: mean (SD), median [IQR], n (%), or leave it out.
- Copy for Word and paste the table into your manuscript. The methods text drafts the footnote.
For trials, pair the table with a CONSORT flow diagram; for survival outcomes, see theKaplan–Meier plot.
Frequently asked questions
What is “Table 1”?
The first table of most clinical and epidemiological papers describes the participants: their characteristics at baseline, overall and by group (treatment arm, exposure, cohort). Readers use it to judge who was studied and whether the groups were comparable.
How are the variables summarised?
Number columns are shown as mean (standard deviation) by default; switch skewed ones, such as CRP or length of stay, to median [interquartile range] with quartiles calculated as in R (type 7). Text columns are shown as number (percentage) of participants with data in each category. Missing values are counted separately and left out of the percentages.
Which tests give the P values?
Means are compared with Student’s t test (two groups) or one-way ANOVA, medians with the Kruskal–Wallis test, and categories with the χ² test (with Yates’ correction for 2 × 2 tables) or, for 2 × 2 tables with an expected count below 5, Fisher’s exact test (a common rule that you can switch off). Each test gives the same P value as the corresponding R function used by the tableone package.
Should a randomised trial report P values in Table 1?
CONSORT advises against significance tests of baseline differences in randomised trials, because any difference is due to chance by design. Untick “P values” for trials; for observational studies P values or standardised differences are common.
How do I get the table into my manuscript?
“Copy for Word” copies a formatted table that pastes into Word or Google Docs as a real table, with the column headings and the test footnote. “Download CSV” gives the same content for Excel. Your data never leaves the browser.