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Bartholomaus S.,Epidemiological Cancer Registry of North Rhine Westphalia | Hense H.W.,University of Munster | Heidinger O.,Epidemiological Cancer Registry of North Rhine Westphalia
Studies in Health Technology and Informatics

Evaluating cancer prevention programs requires collecting and linking data on a case specific level from multiple sources of the healthcare system. Therefore, one has to comply with data protection regulations which are restrictive in Germany and will likely become stricter in Europe in general. To facilitate the mortality evaluation of the German mammography screening program, with more than 10 Million eligible women, we developed a method that does not require written individual consent and is compliant to existing privacy regulations. Our setup is composed of different data owners, a data collection center (DCC) and an evaluation center (EC). Each data owner uses a dedicated software that preprocesses plain-text personal identifiers (IDAT) and plaintext evaluation data (EDAT) in such a way that only irreversibly encrypted record assignment numbers (RAN) and pre-aggregated, reversibly encrypted EDAT are transmitted to the DCC. The DCC uses the RANs to perform a probabilistic record linkage which is based on an established and evaluated algorithm. For potentially identifying attributes within the EDAT ('quasi-identifiers'), we developed a novel process, named 'blinded anonymization'. It allows selecting a specific generalization from the pre-processed and encrypted attribute aggregations, to create a new data set with assured k-anonymity, without using any plain-text information. The anonymized data is transferred to the EC where the EDAT is decrypted and used for evaluation. Our concept was approved by German data protection authorities. We implemented a prototype and tested it with more than 1.5 Million simulated records, containing realistically distributed IDAT. The core processes worked well with regard to performance parameters. We created different generalizations and calculated the respective suppression rates. We discuss modalities, implications and limitations for large data sets in the cancer registry domain, as well as approaches for further improvements like l-diversity and automatic computation of 'optimal generalizations. © 2015 European Federation for Medical Informatics (EFMI). Source

Weigel S.,Medical Faculty and University Hospital Muenster | Heindel W.,Medical Faculty and University Hospital Muenster | Heidinger O.,Epidemiological Cancer Registry of North Rhine Westphalia | Berkemeyer S.,Medical Faculty and University Hospital Muenster | And 2 more authors.

Purpose: To determine the relationship between overall detection rates of ductal carcinoma in situ (DCIS) and the specific detection rates of low-, intermediate-, and high-grade DCIS at the start of a digital mammography screening program. Materials and Methods: The study was approved by the local ethics board and did not require informed consent. Data were included of the first round of digital mammography examinations, performed in 17 screening units in women aged 50-69 years from 2005 to 2008. Grading was provided by the cancer registry for 1018 DCIS cases. The association between the overall cancer detection rate (cases per 100 women screened) and the separate cancer detection rate for invasive cancers and for DCIS was assessed. Likewise, the total DCIS cancer detection rate was separated into rates for low, intermediate, and high grades. Spearman rank correlations were used for analysis. Results: The overall cancer detection rate correlated with both the cancer detection rate of invasive cancers and the cancer detection rate of DCIS (r = 0.96 and r = 0.88, respectively; P < .001 for both). The cancer detection rate of total DCIS with grading varied among screening units (range, 0.05-0.25), it was borderline not significantly correlated with the cancer detection rate of low-grade DCIS (range, 0.004-0.05; r = 0.49; P = .052), and it showed significant correlations with higher cancer detection rate of intermediate-grade DCIS (range, 0.02-0.12; r = 0.89; P < .001) and of high-grade DCIS (range, 0.03-0.11; r = 0.88; P < .001). Conclusion: This study demonstrates that high overall cancer detection rates in digital mammography screening are related to high detection rates of invasive cancers, as well as DCIS. Increases in the detection rates of DCIS were not driven by disproportionate increments of the slowly progressive low-grade subtype but rather by increased rates of intermediate- and high-grade subtypes that carry a higher risk of transition to invasive cancers. © RSNA, 2013. Source

Geier A.S.,University of Munster | Wellmann I.,University of Munster | Wellmann J.,University of Munster | Kajuter H.,Epidemiological Cancer Registry of North Rhine Westphalia | And 3 more authors.
Diabetes Research and Clinical Practice

Aims: We evaluated the patterns and determinants that influence the selection, timing and duration of first-line antihyperglycaemic drug (AHD) treatment in patients with type 2 diabetes in Germany, focusing specifically on treatment-naive AHD initiators. Methods: Pharmacy dispensing claims data were linked with a cohort of patients newly enrolled in a German Disease Management Program for type 2 diabetes (DMP-DM2) between 2003 and 2009. We examined uptake of first-line pharmacotherapy in previously unmedicated patients and identified predictors of receiving AHD therapy in general and metformin in particular using multivariable regression analyses. Results: There were 27,138 unmedicated patients with type 2 diabetes and 47.0% of them were started on AHD treatment within 5 years after enrollment. Initial severity of diabetes was the major predictor of receiving first-line pharmacotherapy. Metformin accounted for 63% of newly prescribed AHD in 2003 and more than 80% in 2009 while sulfonylureas accounted for only 10%. Initiating metformin as first-line AHD was associated with younger age, higher BMI, lower HbA1c, and shorter diabetes duration (multivariate p<. 0.001 for all). Therapy switch or step-up was less frequent among metformin initiators than sulfonylurea initiators. Conclusions: The majority of patients were not started on AHD therapy within 5 years after enrollment. In line with recent therapy guidelines, current first-line antihyperglycaemic treatment was increasingly based on metformin. AHD initiators started on sulfonylurea were generally more advanced in their disease and were started later on primary pharmacotherapy. © 2014 Elsevier Ireland Ltd. Source

Weigel S.,University of Munster | Hense H.W.,University of Munster | Heidrich J.,Epidemiological Cancer Registry of North Rhine Westphalia | Berkemeyer S.,University of Munster | And 2 more authors.

Purpose: To investigate the association between age at screening and detection rates for ductal carcinoma in situ (DCIS) separately for different nuclear grades after introduction of a population-based digital mammography screening program. Materials and Methods: The retrospective study was approved by the ethics board and did not require informed consent. In 733 905 women aged 50-69 years who participated in a screening program for the first time in 2005-2008 (baseline examinations were performed with digital mammography), DCIS detection rates were determined for 5-year age groups (detection rates per 1000 women screened) to distinguish high-, intermediate-, and low-grade DCIS. Multivariable logistic regression was used to compare detection rates between age groups by adjusting for screening units (P <.05). Results: There were 989 graded DCIS diagnoses among 733 905 women (detection rate, 1.35‰):419 diagnoses of highgrade DCIS (detection rate, 0.57‰), 388 diagnoses of intermediategrade DCIS (detection rate, 0.53‰), and 182 diagnoses of low-grade DCIS (detection rate, 0.25‰). Detection rate for types of DCIS combined increased significantly across age groups (50-54 years, detection rate of 1.15‰ [254 of 220 985 women]; 55-59 years, detection rate of 1.23‰ [218 of 177 782 women]; 60-64 years, detection rate of 1.34‰ [201 of 150 415 women]; and 65-69 years, detection rate of 1.71‰ [316 of 184 723 women]; P <.001). Of note, the detection rate for high-grade DCIS showed a significant increase with age (odds ratio, 1.18 per 5-year age group; P <.0001). The increase was lower for intermediate-grade DCIS (odds ratio, 1.11; P =.016) and not significant for low-grade DCIS (P =.10). Conclusion: Total DCIS detection rates increase with age, mostly because of an increase in high- and intermediate-grade DCIS, which are precursor lesions that carry a higher risk for transition to more aggressive invasive breast cancer than low-grade DCIS. © RSNA, 2015. Source

Weigel S.,University Hospital Muenster | Heindel W.,University Hospital Muenster | Heidrich J.,Epidemiological Cancer Registry of North Rhine Westphalia | Heidinger O.,Epidemiological Cancer Registry of North Rhine Westphalia | Hense H.W.,University of Munster
RoFo Fortschritte auf dem Gebiet der Rontgenstrahlen und der Bildgebenden Verfahren

Purpose: The decline in advanced breast cancer stages is presumably the most relevant surrogate parameter in mammography screening. It represents the last step in the causal cascade that is expected to affect breast cancer-related mortality. To assess the effectiveness of population-based screening, we analyzed the 2-year incidence rates of advanced breast cancers between women participating in the initial and in the first subsequent round. Materials and Methods: The study included data from 19 563 initial and 18 034 subsequent examinations of one digital screening unit (2008 - 2010). Data on tumor stages, detected by screening or within the following interval of two years (2-year incidence), were provided by the epidemiological cancer registry. Rates of all and combined UICC stages 2, 3 and 4 (advanced stages) were reported for a two-year period. Proportions were tested for significance by using chi-square tests (p < 0.001). Results: The 2-year incidence rate of all stages was significantly lower in participants in subsequent screening than in initial screening (0.85 vs. 1.29 per 100 women (%); p < 0.0001). A significantly lower 2-year incidence of advanced stages was observed for subsequent screening compared to initial screening (0.26 % vs. 0.48 %; p = 0.0007). Among women aged 50 to 59 years, the incidence of advanced stages was less clearly different (0.21 % vs. 0.35 %; p = 0.07) than in women aged 60 to 69 years (0.31 % vs. 0.70 %; p = 0.0008). Conclusion: During the change from prevalent to incident phase mammography screening, a program impact is seen by a lower 2-year incidence of advanced breast cancers within subsequent compared to initial participants, predominately in women aged 60 to 69 years. Key Points: The incidence of advanced tumor stages represents the most relevant surrogate parameter for screening effectiveness. bull; For the first time the 2-year incidence of advanced breast cancer stages after subsequent mammography screening was analyzed. • We observed a significant effect of screening on the 2-year incidence of advanced stages, predominately in the age group 60 to 69 years. Citation Format: • Weigel S, Heindel W, Heidrich J et al. Reduction of Advanced Breast Cancer Stages at Subsequent Participation in Mammography Screening. Fortschr Röntgenstr 2016; 188: 33-37 © Georg Thieme Verlag KG Stuttgart · New York. Source

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