#Dex online reverse search trial

If the method was used, the coordinator was to put “+++,” “++,” “+,” or “−“. They were instructed to leave the box for a specific method blank if the method was not used. In April 2010, coordinators were sent the spreadsheet and asked to subjectively assess the degree to which each specific method was used by his or her center over the entire course of both studies. Methods were grouped into three categories: those using information from study forms (PLCO: BLF, FLF LSS: PCF 12 methods), those using sources other than study forms not geared towards deaths (9 methods), and those using sources other than study forms that were geared towards deaths (6 methods). A spreadsheet was then developed that included all the methods used.

For the purpose of the current investigation, center coordinators were asked to submit lists of methods employed for tracking and tracing. This process of keeping track of participants and tracing them when lost was intensive and time-consuming, yet it had to be done accurately and thoroughly, as the success of the trials depended on the ability to capture the vital status of all participants.Įach center chose its tracking and tracing methods. If the participant could not be located using these methods, other techniques were employed to find the participant or to determine if the participant was deceased. If the ASU was not returned, the center repeated the mailing if that failed, the participant was telephoned. This information was collected annually through a self-administered form, the ASU, which was mailed to participants. The centers were responsible for collecting vital status information on all participants. Table 1 displays center name, location, and enrollment for each study. The same ten screening centers participated in both PLCO and LSS.

#Dex online reverse search trial

Participants in both trials were between the ages of 55 to 74 at trial entry and were healthy. The LSS enrolled over 34,000 participants from 2002 to 2004, and each participant received a minimum of five-and-a-half years of follow-up. PLCO enrolled nearly 155,000 participants from 1993 to 2001, and each participant received a minimum of 10 years of follow-up.

PLCO and the LSS component of the National Lung Screening Trial, described in detail elsewhere, were two large randomized controlled trials designed to assess the ability of certain screening regimens to reduce cancer-specific mortality.