Shared decision-making in older patients with colorectal or pancreatic cancer: Determinants of patients’ and observers’ perceptions

To identify determinants of older patients’ perceptions of involvement in decision-making on colorectal (CRC) or pancreatic cancer (PC) treatment, and to compare these with determinants of observers' perceptions. Patients’ perceptions of involvement were constructed by the 9-item SDM questionnaire (SDM-Q-9) and a Visual Analogue Scale for Involvement (VAS-I). Observers’ perceptions were constructed by the OPTION5, OPTION12, and MAPPIN’SDM. Convergent validities were calculated between the patient-sided and observer instruments using Spearman’s correlation coefficient. Linear regression was used to identify determinants per criterion. 58 CRC and 22 PC patients were included (mean age: 71.8 ± 5.2 years, 45.0% female). No significant correlations were found between the patient-sided and observer instruments. Patients’ impression of involvement was influenced by patient characteristics such as quality of life and satisfaction, while observers’ perceptions mainly referred to encounter characteristics such as the mean duration of consultations and general communication skills. Due to evident differences in determinants, older CRC/PC patients’ and observers’ perceptions of involvement should both be collected in evaluating the quality of medical decision-making. General communication skills should be integrated in SDM training interventions. New SDM measurement tools for patients are needed to sufficiently discriminate between the constructs of involvement and satisfaction.