Background: We aimed to analyze preferred and perceived levels of patients' involvement in treatment decision-making in a representative sample of cancer patients.Material and Methods: We conducted a multicenter, epidemiological cross-sectional study with a stratified random sample based on the incidence of cancer diagnoses in Germany. Data were collected between January 2008 and December 2010. Analyses were undertaken between 2017 and 2019. We included 5889 adult cancer patients across all cancer entities and disease stages from 30 acute care hospitals, outpatient facilities, and cancer rehabilitation clinics in five regions in Germany. We used the Control Preferences Scale to assess the preferred level of involvement and the nine-item Shared Decision-Making Questionnaire to assess the perceived level of involvement.Results: About 4020 patients (mean age of 58 years, 51% female) completed the survey. Response rate was 68.3%. About a third each preferred patient-led, shared, or physician-led decision-making. About 50.7% perceived high levels, about a quarter each reported moderate (26.0%) or low (24.3%) levels of shared decision-making. Sex, age, relationship status, education, health care setting, and tumor entity were linked to preferred and/or perceived decision-making. Of those patients who preferred active involvement, about 50% perceived high levels of shared decision-making.Conclusion: The majority of patients with cancer wanted to be involved in medical decisions. Many patients perceived a high level of shared decision-making. However, many patients' level of involvement did not fit their preference. This study provides a solid basis for efforts to improve shared decision-making in German cancer care.
