Treatment decision-making among patients with metastatic prostate cancer: Impact of decision locus of control on functional outcomes and decision satisfaction.

BACKGROUND: Shared decision-making (SDM) for metastatic prostate cancer (mPC) engages patients in the decision-making process and may be associated with better outcomes relative to physician- or patient-directed decision-making. We assessed the association between decision locus of control (DLOC) and patient-reported quality of life (QOL), functional outcomes, and decision satisfaction among mPC patients. METHODS: After a clinic visit in which a treatment decision was made (baseline), mPC patients completed DLOC and QOL surveys. QOL was re-assessed at 2- and 4-months post-baseline. Mean scores for each QOL dimension (physical, emotional, cognitive, social, and role functioning) were compared by DLOC group using mixed effects models. Patient preferences for DLOC and provider communication techniques were similarly collected via survey. RESULTS: Median age of participants (N = 101) was 69 years (range: 49-92); most were White (80%) and married (82%). 62% reported using SDM. At baseline, there were no differences in QOL dimensions between DLOC groups. At 4 months, patient-directed (p = 0.01) and SDM (p = 0.03) were associated with better physical functioning than physician-directed decision-making, and there was an indication of potentially greater decision satisfaction among patients who reported patient-directed (p = 0.06) or SDM (p = 0.10). SDM was the most reported preferred DLOC. CONCLUSION: mPC patients reporting SDM had better physical functioning at 4 months than physician- or patient-directed decision-making, suggesting measurable benefit from patient involvement in decision-making. Future investigations of these associations in larger, more diverse populations can further clarify these previously unmeasured benefits of patient engagement in treatment decisions.

Treatment Decision-Making in Metastatic Prostate Cancer: Perceptions of Locus of Control Among Patient, Caregiver, and Physician Triads.

BACKGROUND: Multiple treatments for metastatic prostate cancer have similar efficacy, leaving patients with complicated treatment choices. Shared decision-making can facilitate difficult treatment decisions, but the extent to which this is used for metastatic prostate cancer is unknown. We assessed patient, caregiver, and physician perceptions of decision locus of control (shared decision-making vs physician- or patient-directed decisions) and the degree of agreement between groups. METHODS: Triads of patients, caregivers, and physicians completed surveys of decision-making practices after a clinic visit in which a decision occurred. To evaluate the degree of agreement for decision locus of control, we used the quadratic-weighted kappa coefficient (κ). We used relative frequencies to evaluate which knowledge learned and treatment factors were most strongly endorsed by patients as informing and influencing their treatment decision-making, respectively. RESULTS: Fifty triads participated, with median patient age of 72 years. A majority of patients, caregivers, and physicians reported shared decision-making (66%, 56%, and 52%, respectively). Patients and physicians demonstrated minimal agreement about decision locus of control (44%, κ=0.35 [SD = 0.52]), but caregiver reports were not statistically significantly associated with physician and patient reports (38%, κ=0.23, [SD = 0.28]), p=0.055; 44%, κ=0.34 [SD = 1.98], p=0.14). Treatment efficacy was the most common patient-reported factor influencing treatment decisions (44%). CONCLUSION: This study characterized metastatic prostate cancer patients', caregivers', and physicians' experiences and communication preferences for treatment decision-making. Patients and physicians had greater agreement in decision locus of control compared with caregivers, yet patient-physician agreement was minimal. Metastatic prostate cancer patients report being influenced by information about treatment efficacy and clear next steps, and a desire for patient-friendly language and an invitation to be as involved in decision making at their preferred level. Emphasizing these may increase agreement in decision locus of control between all participants in the decision-making process.