Diagnostic Validity of Chronic Kidney Disease in Health Claims Data Over Time: Results from a Cohort of Community-Dwelling Older Adults in Germany

Abstract

Purpose

The validity of ICD-10 diagnostic codes for chronic kidney disease (CKD) in health claims data has not been sufficiently studied in the general population and over time.

Patients and Methods

We used data from the Berlin Initiative Study (BIS), a prospective longitudinal cohort of community-dwelling individuals aged ≥70 years in Berlin, Germany. With estimated glomerular filtration rate (eGFR) as reference, we assessed the diagnostic validity (sensitivity, specificity, positive [PPV], and negative predictive values [NPV]) of different claims-based ICD-10 codes for CKD stages G3-5 (eGFR <60mL/min/1.73m²: ICD-10 N18.x-N19), G3 (eGFR 30–<60mL/min/1.73m²: N18.3), and G4-5 (eGFR <30mL/min/1.73m²: N18.4–5). We analysed trends over five study visits (2009–2019).

Results

We included data of 2068 participants at baseline (2009–2011) and 870 at follow-up 4 (2018–2019), of whom 784 (38.9%) and 440 (50.6%) had CKD G3-5, respectively. At baseline, sensitivity for CKD in claims data ranged from 0.25 (95%-confidence interval [CI] 0.22–0.28) to 0.51 (95%-CI 0.48–0.55) for G3-5, depending on the included ICD-10 codes, 0.20 (95%-CI 0.18–0.24) for G3, and 0.36 (95%-CI 0.25–0.49) for G4-5. Over the course of 10 years, sensitivity increased by 0.17 to 0.29 in all groups. Specificity, PPVs, and NPVs remained mostly stable over time and ranged from 0.82–0.99, 0.47–0.89, and 0.66–0.98 across all study visits, respectively.

Conclusion

German claims data showed overall agreeable performance in identifying older adults with CKD, while differentiation between stages was limited. Our results suggest increasing sensitivity over time possibly attributable to improved CKD diagnosis and awareness.

Keywords:

• CKD
• diagnostic validity
• health claims data
• sensitivity
• specificity

Data Sharing Statement

The data used in this study cannot be made available in the manuscript, the Supplementary Files, or in a public repository due to German data protection laws (Bundesdatenschutzgesetz). To facilitate the replication of results, the used data will be stored on a secure drive at Charité – Universitätsmedizin Berlin. Access to the raw data used in this study can only be provided to external parties under the conditions of a cooperation contract and can be accessed upon request, after written approval ([email protected]), if required.

Acknowledgments

We greatly thank the AOK Nordost – Die Gesundheitskasse for providing the health claims data of the BIS participants and supporting this study.

Author Contributions

TB, NE, ES, and AD conceptualised and designed the study and study protocol. Data were provided by ES, NE, NM, and VW. TB carried out the data analysis supported by AKF and AP. TB, NE, AKF, and AP interpreted the data. The manuscript was drafted by TB, substantially revised by NE, ES, and AD, and critically reviewed by AKF, AP, NM, CV, MHB, and VW. TB and AKF have accessed and verified the study data. All authors gave final approval of the version to be published and agreed on the journal to which the article was submitted. All authors agree to take responsibility and be held accountable for the contents of the article.

Disclosure

NE received grants by Bayer AG. ES receives honorarium from AstraZeneca for counseling and from the National Kidney Foundation for editorial work for the American Journal of Kidney Diseases. All other authors have nothing to declare for this work.

Additional information

Funding

This research was partly funded by the Federal Joint Committee’s innovation fund (project GUIDAGE-CKD; funding code 01VSF20020). The funding institution was not involved in planning, conducting, interpreting, or publishing of this study.