Consultations of patients with cancer to enhance shared decision-making in Japan: A retrospective observational study.

Purpose: Treatment decisions are often highly complex when the outcomes are uncertain. In Japan, the consultation fees incurred can be reimbursed when physicians and nurses work together with patients to provide shared decision-making (SDM) on treatment plans. However, the extent to which reimbursed consultations are used by clinicians is unclear. This study aimed to determine the extent to which so-called "reimbursed SDM consultations" are used in cancer treatment and to identify the characteristics of patients having these consultations using a nationwide database.

Methods: This retrospective study used health service utilization data linked to hospital-based cancer registries from 591 hospitals in Japan. Data for patients aged 18 years or above diagnosed with cancer in 2019 were analyzed. Multivariable logistic regression analysis was conducted to analyze the association between reimbursed SDM consultations and patient characteristics.

Results: Overall, 74,828 patients (12.2%) received reimbursed SDM consultations in 533 hospitals. The presence of breast cancer (odds ratio (OR) = 2.00), treatment types of radiotherapy (OR = 1.86) and pharmacotherapy (OR = 1.76), and distant metastasis (OR = 1.49) and the invasion of adjacent organs (regional) (OR = 1.47) were positively associated with reimbursed SDM consultations. Cervical (OR = 0.38) and renal cancers (OR = 0.49) were negatively associated with reimbursed SDM consultations.

Conclusion: This study is the first to determine the extent to which reimbursed SDM consultations are used and the characteristics of the patients receiving them. Further studies should investigate the factors influencing the use of reimbursed SDM consultations.