“Primary Completion Date” is the date that the final subject was examined or received an intervention for the purposes of final collection of data for the primary outcome, whether the clinical trial concluded according to the prespecified protocol or was terminated. In many oncology trials, this will be different from the “Study Completion Date” because many primary outcome measures have shorter time frames than secondary outcome measures. For example, a primary outcome measure may be tumor progression at 6 months whereas a secondary outcome measure may be survival rates at 5 years.
“Study Completion Date” is the final date on which data was collected. This may coincide with Primary Completion Date, depending upon whether the time frames for the primary outcome measures and the secondary outcome measures were the same or different.
