Table 3.

Discrepancies in components of results reporting for outcomes reported in both preprints and journal publications (N=67 studies; 258 outcomes)

Type of discrepancy	Number (%) of studies with at least one discrepancy between the preprint and journal publication (n=67)	Number (%) of outcomes across all studies that were discrepant between the preprint and journal publication (n=258)	Descriptive examples*
Outcome measurement	6 (9%)	8 (3%)	Journal publication contains more detail on how outcome was measured compared with preprint (n=3) Journal publication reports an additional or different measurement than the one used for the same outcome in the preprint (eg, preprint reports four adverse events, journal publication reports 12) (n=4)
Units of measurement	3 (4%)	3 (1%)	For example, journal publication reports events, total and percentage for mortality, preprint reports only percentage; median (IQR) reported in journal publication, mean (SD) in preprint
Timepoint assessment was made	10 (15%)	24 (9%)	Journal publication reports outcomes measured over a longer timepoint than preprint (n=13) Journal publication reports additional interim time points compared with preprint (n=3)
Numerical values reported	24 (36%)	52 (20%)	Differences in number of events or measurement values reported (n=17) Differences in numbers of participants or denominators (n=5) More adverse events reported in journal publication than preprint (n=4)
Finding of statistical significance	11 (16%)	16 (6%)	Different p-value reported with no change in significance (n=3) Different p-value reported with change in significance; significant result reported in journal publication (n=1) In multivariate models, journal publication and preprint report different variables as being statistically significant (n=2)
Statistical tests performed	17 (25%)	31 (12%)	Journal publication contains additional statistical analysis compared with preprint (n=7) Journal publication uses different statistical adjustments compared with preprint (n=7) Journal publication and preprint use different statistical tests for same data (n=3)
Subgroup analyses conducted	14 (21%)	24 (9%)	Journal publication includes subgroup analysis not included in preprint (n=6) Journal publication finds statistically significant interaction for subgroup, preprint does not (n=1)
Identifying the outcome as a primary or secondary outcome	1 (1%)	3 (1%)	For example, preprint identifies the primary endpoint as safety; journal publication adds the secondary endpoint of exploration of efficacy

*Ns do not add to number of reported discrepancies as some studies could have more than one discrepancy and not all discrepancies have been included as examples.