Monday, October 24, 2011
Grand Ballroom AB (Hyatt Regency Chicago)
Poster Board # 22
(DEC) Decision Psychology and Shared Decision Making

Dana L. Alden, PhD, University of Hawaii at Manoa, Honolulu, HI, Qimei Chen, PhD, University of Hawaii, Honolulu, HI and Jennifer Aaker, PhD, Standford University, Palo Alto, CA

Purpose: A 2009 Cochrane review points to multiple positive outcomes associated with patients using decision aids (PDAs) to assist treatment/screening decisions. PDAs are known to reduce decision conflict and passive decision-making. However, research that includes PDA exposure in a larger theoretical net with individual difference factors such as “desire for information/control” (HOS) and “life satisfaction” (LS) is limited.  A recently developed scale (CAS) measures cancer treatment self-efficacy to understand/participate (CAS1) and maintain a positive attitude (CAS2).  This study employs representative adult panel samples and a scenario-based method to investigate PDA versus HOS and LS effects on CAS1 and CAS2.

Method: Two online panel samples in the US totaling 935 adults (age 23-81, mean=50; 54% female/46% male) were exposed to a scenario in which they were recently diagnosed with basal cell carcinoma and about to meet with their dermatologist to decide on treatment. The first group (n=522) viewed a PDA with treatment cost/benefit information and values exploration. The second group (n=413) received limited information about the diagnosis. Respondents in the first group evaluated the PDA very positively using standard measures. Given minimal between group differences, analyses were conducted on the overall sample.    

Result: PCA identified the same factor structure for CAS found in earlier research. Two regression models were run with CAS1 and CAS2 as dependent measures. Age and gender were included as controls along with perspective taking, which was added to control for possible differences in scenario visualization ability. Both HOS (β’s=.24, .13) and LS (β’s=.12, .24) were positively related to CAS1 and CAS2 (p<.001). Despite inclusion of two individual difference predictors and three controls, PDA versus no PDA marginally enhanced CAS1 (β=.06; p=.075) and significantly enhanced CAS2 (β=.08; p=.007).  Stepwise regression produced similar results.

Conclusion: This study provides further evidence of CAS scale validity as a measurement tool for patients with newly diagnosed cancer.  More importantly, the study finds PDA effects on cancer self-efficacy in the presence of theoretically relevant individual difference factors. Effects were marginally significant for “ability to understand/participate” and significant for “ability to maintain a positive attitude.” Given larger beta weights for individual difference factors, providers are advised to consider their patients’ psychological predispositions such as HOS and LS in addition to PDA exposure when evaluating cancer self-efficacy.