Medical Care and Survival of Soft-Tissue and Bone Sarcoma Patients: Results and Methodological Aspects of a German Subnational Cohort Study Based on Administrative Healthcare Data

Abstract
Introduction: Medical care of soft-tissue sarcoma (STS) and bone sarcoma (BS) patients in Germany has rarely been investigated. The objectives of this article were (1) to investigate medical care and survival in STS and BS patients, and (2) to examine methodological aspects of corresponding analyses based on administrative healthcare data. Methods: We analyzed data from a statutory health insurance located in Saxony, Germany, covering approximately 2 million individuals. We identified incident STS and BS patients in the period 2012–2016 using 4 different case definitions. We examined treatment rates and visits to medical oncologists and medical practices descriptively, and then compared results between case definitions. We investigated survival prospects using a relative survival analysis and estimated hazard ratios (HRs) for risk factors for mortality using Cox regression. Results: Across case definitions, the number of included sarcoma patients (STS: n = 871–1,757; BS: n = 216–689) and applied treatments (STS: 42.2–83.1%; BS: 28.3–77.8%) varied substantially. Irrespective of the case definition, the minority of patients visited medical oncologists (STS: 9.8–10.8% BS: 4.4–7.9%) and “experienced” medical practices (STS: 27.7–38.4%; BS: 18.3–23.6%). Survival prospects were better for patients who visited “experienced” medical practices (STS: HR = 0.55; BS: HR = 0.42). Conclusion: Treatment rates clearly <100% and evidence from survival analyses indicate the potential for improvements in the care of sarcoma patients in Germany, e.g., by physicians in “experienced” medical practices.