CTRI requirement of prospective trial registration: Not always consistent.

In a clinical trial registry, one determines whether a trial is registered prospectively or retrospectively by comparing the date of registration with the date on which enrollment started. However, in Clinical Trials Registry - India (CTRI), in addition, the top of each record is labelled with the phrase "Trial Registered Prospectively" or "Trial Registered Retrospectively". In examining CTRI records, we have found that (a) although retrospective registration has been disallowed from April 1, 2018, some trials were registered retrospectively; (b) in some cases, enrollment started after registration, even though they were labelled "Trial Registered Retrospectively", which is misleading; and (c) in some cases, the date of first enrollment was modified, changing a retrospective registration to a prospective one, although the label "Trial Registered Retrospectively" persisted. This, too, is misleading. The CTRI administration should take suitable steps to prevent late registration and mislabelling of trials regarding their registration status.