A lesson learned from the collection of patient-reported
information in prospective clinical trials and registries is
that the frequency of missing patient reports is highly
dependent on how this information is collected. In particular,
data can be recovered from those who are initially
unable or unwilling to self-report, through the use of
backup data collection methods. These may include electronic
reminders via mail, email or telephone, with a
human call to those who continue not to report. This
approach requires a near-real-time monitoring system for
who complies and who does not, in order to identify
individuals for targeted backup data collection.