Monday, October 20, 2014: 5:00 PM

Ellen G. Engelhardt, MSc.1, Anine J. Griffioen, BSc.1, Nanny van Duijn-Bakker, BSc.1, Anja van der Hout, MSc.1, Ellen MA Smets, PhD2, J. (Hanneke) CJM de Haes, PhD2, Arwen H. Pieterse, PhD1 and Anne M. Stiggelbout, PhD1, (1)Leiden University Medical Center, Leiden, Netherlands, (2)Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
Purpose: Deciding about adjuvant hormonal and/or chemotherapy for breast cancer can be difficult. Many factors, medical as well as personal, need to be considered. Currently, there is no consensus about which instrument best captures patient involvement in decision-making, or whom (patient or observer) can best determine it. We used the Control Preferences Scale (CPS) to determine the actual involvement patients experienced and their involvement as assessed by observers.

Method: We audiotaped and transcribed consultations with oncologists in which hormonal and/or chemotherapy was discussed. Based on these transcripts, two researchers independently assessed the patient’s level of involvement using the CPS categories. Within three days after the consultation patients were interviewed by telephone and asked whom they felt had made the final treatment decision (open-ended question). Two other researchers independently coded the patient’s answer using the CPS categories.  

Result: We included 67 patients, involved in a total of 84 decisions about hormonal and/or chemotherapy. On average they were 61 years (range: 38-87) and 30% was highly educated. Overall, agreement between patients and observers about who had made the final treatment decision was 49% with a Kappa of 0.16 (95% CI 0 – 0.33). According to both patients (chemotherapy 6% and hormonal therapy 14%) and observers (chemotherapy 8% and hormonal therapy 2%) few decisions were shared. For both hormonal (68% vs. 26%) and chemotherapy (72% vs. 41%) decisions, patients more often indicated that they had made the final decision themselves than the observers. However, irrespective of assessor, patients seem to be more involved in chemotherapy than in hormonal therapy decisions.

Conclusion: The observers’ assessment of patients’ actual involvement in decision-making differed from the patients’ assessment, with patients experiencing a higher level of involvement. According to the  observers’ assessment, patients were rarely involved in hormonal therapy decisions. Results suggest that observers are less lenient when it comes to judging behavior as participation than patients.