OBJECTIVES: The burden of disease in cancer is increasing despite significant advancements in medical technology. Germany introduced accreditation of local provider networks as organ cancer centers to assure quality and to develop oncological care structures. However, uneven accreditation uptake across regions limits access of certain patient populations. Accreditation is associated with improved treatment outcomes but causal effects cannot be assumed with certainty and regional interdependencies have not yet been analyzed. The objective of the study is to assess the effect of the accreditation of specialized cancer care on patient survival while accounting for geospatial correlation.

METHODS: We combine accreditation, epidemiologic, socioeconomic and innovation activity data from the year 2000 until 2018 on the regional level for 401 districts in Germany. We use a spatial difference-in-difference approach to estimate the causal effect of accreditation on cancer survival after diagnosis for eight cancer sites. We account for regional spillover effects.

RESULTS: After adjusting for patient characteristics and regional innovation activity, linear regression suggests that patients who lived in regions with at least one accredited center related to their cancer type had a 7.6 (p≤0.000) percentage points lower probability to die within five years after diagnosis. Among the patients who died, the survival times in accredited regions increased by 0.62 (p≤0.000) month for each additional center. Full results will be available in November 2023. We expect spillover effects between nearby districts.

CONCLUSIONS: We contribute to the literature by a) identifying a causal effect of accreditation of specialized cancer care on survival of cancer patients, b) accounting for innovation activities as a major driver of improved survival rates of cancer patients, and c) accounting for spillovers between cancer treatment networks. The results will contribute to inform and develop the strategies of provider organizations and health policy.