Читать книгу Individual Participant Data Meta-Analysis - Группа авторов - Страница 87

Checking IPD, and harmonisation across trials, are integral and necessary components of an IPD meta‐analysis project. The checking process ensures that any missing data, or major errors in the supplied IPD, can be identified and brought diplomatically to the attention on the trial investigators. Often, the problems that arise turn out to be simple errors or reflect misunderstandings, which can be resolved readily, with major problems being rare. As well as preventing serious issues in the meta‐analysis, checking the IPD also promotes a better understanding of each trial by the central research team, and their independent scrutiny of the IPD can enhance the IPD project’s credibility.

Often trials will have collected and defined data items in a variety of ways, and it will be necessary to re‐code or re‐define certain variables to a common format, in preparation for meta‐analysis. Depending on how data have been provided, and whether trial teams have followed the supplied data dictionary, this can be an involved process, as described next. Checking and harmonising data requires care and meticulous attention to detail, in order to avoid misunderstandings and the introduction of errors. Contact with those supplying data may be needed to resolve any uncertainties or sanction particular changes.