IPD integrity

Task: Describe what aspects of IPD were subject to data checking (such as sequence generation, data consistency and completeness, baseline imbalance) and how this was done.

Text: The IPD are first checked for consistency against published reports or the trial to confirm, for example, that the number of patients and events is consistent with reports of the trial. The IPD are then processed to create standardized dataset, which are then subject to a series of checks relating to the sequence that patients were randomized, the balance of variables within the group, range checks on the variables to identify outliers or invalid values, and cross tabulations to determine consistency in related variables. Some of these checks might not be possible because of the provision of data on for example, the interval between events (such as randomisation and recurrence), rather than the actual dates of the events.