High rate of consent to bank biologic samples for future research: the Eastern Cooperative Oncology Group experience

The Eastern Cooperative Oncology Group (ECOG) requires patient consent for the storage and future use of samples left over from its therapeutic cancer clinical trials. The ECOG consent instrument evolved from a simple statement requiring a signature to a more detailed three-question format. Between February 1998 and October 2000, more than 7000 patients were accrued to studies using one of the two consent forms. We analyzed our consent response data by consent type, demographic information, disease site, and institution type to determine the assent rates for future storage and research on biologic samples and to identify possible factors predicting patient refusal. The assent rate for the original banking consent statement was 89.4%, whereas that for the more detailed consent form was 93.7%. Higher assent rates were statistically significant for the detailed consent form versus the original consent form (P=.001), for community-based practices versus academic centers (P<.001), and for patients aged at least 65 years versus those younger (P=.002). The results show that increased patient protection does not result in decreased availability of biologic samples for future research purposes.