Satisfaction with the decision to participate in cancer clinical trials is high, but understanding is a problem

Abstract

Background: Partially presented in poster format at the 40th and 41st Annual Meetings of the American Society of Clinical Oncology, held in 2004 in New Orleans, Louisiana and in 2005 in Orlando, Florida.

Purpose: We aimed to: (a) assess patient knowledge about cancer clinical trials (CCT) and satisfaction with their decision to participate, (b) determine whether satisfaction correlates with objective understanding, or other factors, and (c) identify correlates of increased understanding.

Methods: A convenience sample of 100 patients were recruited. Instruments assessed quality of informed consent (QuIC), quality of life (EORTC QLQ C-30), anxiety and depression (HADS), and preferences for information and involvement in decision making. Measures were completed within 2 weeks of clinical trial enrollment.

Results: One hundred two patients (68 male) with a median age of 58.4 years (29-85) were registered in 27 of the 33 therapeutic cancer clinical trials approved for the Consent Study. Mean QuIC objective knowledge (QuIC-A) was 77.6 (/100) (95% CI, 75.7-79.4) and perceived (subjective) understanding (QuIC-B) 91.5 (95% CI, 89.6-93.3). There was low but significant correlation between QuIC-A and B (R = 0.26, p = 0.008). Satisfaction was very high. Correlation between QuIC-B and satisfaction was moderate (0.430, p < 0.001). QuIC-B, but not QuIC-A was associated with QOL scores. Preferences regarding participation in decision making and whether these preferences were achieved did not impact upon knowledge, understanding or satisfaction.

Conclusions: Patient knowledge regarding CCT is similar to published US data, and satisfaction is high. Satisfaction correlates with perceived but not objective understanding of CCT. Strategies to further improve the consent process need to be developed.