From March 1997 through September 1998, a streamlined endpoint review and closure process was followed. Three changes were implemented for this period: 1) a single reviewer adjudicated all cases independently, unless questions arose; 2) for all cancers other than lung cancer, only pathology reports were required to confirm the endpoint; and 3) only the death certificate was required to confirm cause of death. The process was further streamlined in October 1998, allowing for review by endpoint specialists from the CARET Coordinating Center staff and a single reviewer from the ERC.

The final change came in October 2003 when, as a cost-saving measure, we eliminated the collection and review of pathology reports and began relying solely on self-reports of cancer. Our decision to make this change was based on an evaluation of the accuracy of participant self-report of cancer, especially lung cancer, our primary endpoint. We examined the adjudication outcome of participant reported cancers and found that 91% of cases reported as lung cancer were closed as such. Most of the discrepancies in reporting were due to reporting recurrences or reporting metastases as new primaries. The confirmation rates were high for other commonly reported cancers as well, including prostate (96%), breast (94%), bladder (97%), and colorectal (88%). These findings assured us that self-report of cancer was an acceptable procedure. Based on this evaluation, we made several modifications to the data collection questionnaire to address the reasons for self-reported diagnoses with the review of medical records. In the majority of cases, this was concerned with differentiating a new primary cancer from recurrent, metastatic, and benign diseases. Thus, actual rates of agreement during the self-reporting period (October 2003 – June 2005) are likely higher than we observed in our evaluation.

 • Number of deceased participants by cause of death and intervention arm assignment (PDF)