Evaluation of an indirect record linkage method in an exemplary study on the risk of cancer and cancer mortality in type 2 diabetes patients treated with different antidiabetics

法定健康保险提供者的索赔数据是卫生服务流行病学研究和药物安全性研究的重要资源。这些数据的受益源于大量患者和长期随访的可能性，从而有机会研究非常罕见的药物不良反应和潜伏期较长的药物不良反应。缺乏关于疾病的重要信息，如肿瘤分期或死亡原因，因为收集数据是为了计费，而不是主要用于研究目的。此外，数据中肿瘤诊断的有效性未知。将索赔数据与癌症登记处的数据联系起来，可提供缺失的信息，从而为调查致癌物质的影响作出重要贡献。在本研究提案中，对接受不同抗糖尿病治疗的2型糖尿病患者的癌症风险和癌症死亡率进行了一项示例性研究，旨在评估使用不同方法将匿名索赔数据与德国流行病学癌症登记数据联系起来，在何种程度上更容易获得数据。首先，将使用出生年份、性别、社区代码和肿瘤诊断日期/季度进行间接记录关联。第二，结果将通过一个完善的和准确的，但精心设计的联系程序使用所谓的控制数字进行评估。由于这种联系需要非常严格的数据保护概念，并且非常耗时，因此并非对每个研究问题都可行。使用示例性研究，将描述和评估两个链接数据集之间的质量差异。该项目的总体目标是优化这两种方法的联系程序，以便就进一步研究的成本和时间效率以及具体的数据保护要求提出建议。此外，还将提出建议，说明在何种情况下两种联系程序中的任何一种都能得出有效的调查结果。该项目的结果将分发给德国使用二手数据的研究人员。

Claims data of statutory health insurance providers are an important resource for epidemiological studies in health services and drug safety research. The benefit of these data stems from the large number of patients and the potential for long follow-up periods offering the opportunity to investigate both very rare adverse drug reactions and adverse drug reactions with long latency times. Important information about diseases such as tumor stage or cause of death are lacking since the data was collected for billing and not primarily for research purposes. Furthermore, the validity of tumor diagnoses in the data is unknown. A linkage of claims data with data from a cancer registry provides the missing information, thereby making an essential contribution to the investigation of the effects of carcinogenic substances. In this research proposal, an exemplary study of cancer risk and cancer mortality in type 2 diabetes patients treated with different antidiabetic therapies serves to evaluate to which extent easier data access can be facilitated using different methods of linking pseudonymized claims data to data from epidemiological cancer registries in Germany. First, an indirect record linkage will be performed using year of birth, sex, community code, and date/quarter of the tumor diagnosis. Second, the results will be evaluated by a well-established and exact, yet elaborate linkage procedure using so-called control numbers. As such a linkage requires a very stringent data protection concept and is very time-consuming, it is not feasible for every research question. Using the exemplary study, the differences in quality between the two linked datasets will be described and assessed. The overall objective of this project is to optimize the linkage procedures of both methods in order to give recommendations for the cost and time-efficient conduct of further studies with specific data protection requirements. Furthermore, recommendations will be given under which circumstances either one of the two linkage procedures will lead to valid findings. The results of the project will be disseminated to researchers using secondary data in Germany.