A Validated Algorithm for Register-Based Identification of Patients with Relapse of Clinical Stage I Testicular Cancer

Abstract

Purpose

The Danish Testicular Cancer (DaTeCa) database aims to monitor and improve quality of care for testicular cancer patients. Relapse data registered in the DaTeCa database rely on manual registration. Currently, some safeguarding against missing registrations is attempted by a non-validated register-based algorithm. However, this algorithm is inaccurate and entails time-consuming medical record reviews. We aimed (1) to validate relapse data as registered in the DaTeCa database, and (2) to develop and validate an improved register-based algorithm identifying patients diagnosed with relapse of clinical stage I testicular cancer.

Patients and Methods

Patients registered in the DaTeCa database with clinical stage I testicular cancer from 2013 to 2018 were included. Medical record information on relapse data served as a gold standard. A pre-specified algorithm to identify relapse was tested and optimized on a random sample of 250 patients. Indicators of relapse were obtained from pathology codes in the Danish National Pathology Register and from diagnosis and procedure codes in the Danish National Patient Register. We applied the final algorithm to the remaining study population to validate its performance.

Results

Of the 1377 included patients, 284 patients relapsed according to the gold standard during a median follow-up time of 5.9 years. The completeness of relapse data registered in the DaTeCa database was 97.2% (95% confidence interval (CI): 95.2–99.1). The algorithm achieved a sensitivity of 99.6% (95% CI: 98.7–100), a specificity of 98.9% (95% CI: 98.2–99.6), and a positive predictive value of 95.9% (95% CI: 93.4–98.4) in the validation cohort (n = 1127, 233 relapses).

Conclusion

The registration of relapse data in the DaTeCa database is accurate, confirming the database as a reliable source for ongoing clinical quality assessments. Applying the provided algorithm to the DaTeCa database will optimize the accuracy of relapse data further, decrease time-consuming medical record review and contribute to important future clinical research.

Keywords:

• testicular cancer
• relapse
• algorithm
• validation
• registries

Data Sharing Statement

The data are stored at The Danish Clinical Quality Program – National Clinical Registries (RKKP). The data is not publicly available due to the Danish data protection legislation as the data contains information that could compromise the privacy of the research participants.

Ethics

The study is approved by the Danish Data Protection Agency, approval no. VD-2018–433, the Regional Ethics Committee, approval no. SJ-690, and the Danish Patient Safety Authority, approval no. 31-1521-341.

Disclosure

Daniel M Berney and Gedske Daugaard are co-senior authors for this study. Daniel M Berney is supported by Orchid. The authors report no other conflicts of interest in this work.

Additional information

Funding

The study is supported by the Danish Clinical Quality Program – National Clinical Registries, the Danish Cancer Society, the Danish Cancer Research Foundation, and Preben and Anna Simonsen’s Foundation. The funding sources had no influence on study conceptualization, data collection, data analysis or manuscript preparation.