Validity of Major Osteoporotic Fracture Diagnoses in the Danish National Patient Registry

Abstract

Objective

To evaluate the validity of diagnosis codes for Major Osteoporotic Fracture (MOF) in the Danish National Patient Registry (NPR) and secondly to evaluate whether the fracture was incident/acute using register-based definitions including date criteria and procedural codes.

Methods

We identified a random sample of 2400 records with a diagnosis code for a MOF in the NPR with dates in the year of 2018. Diagnoses were coded with the 10th revision of the International Classification of Diseases (ICD-10). The sample included 2375 unique fracture patients from the Region of Southern Denmark. Medical records were retrieved for the study population and reviewed by an algorithmic search function and medical doctors to verify the MOF diagnoses. Register-based definitions of incident/acute MOF was evaluated in NPR data by applying date criteria and procedural codes.

Results

The PPV for MOF diagnoses overall was 0.99 (95% CI: 0.98;0.99) and PPV=0.99 for the four individual fracture sites, respectively. Further, analyses of incident/acute fractures applying date criteria, procedural codes and using patients’ first contact in the NPR resulted in PPV=0.88 (95% CI: 0.84;0.91) for hip fractures, PPV=0.78 (95% CI: 0.74;0.83) for humerus fractures, PPV=0.78 (95% CI: 0.73;0.83) for clinical vertebral fractures and PPV=0.87 (95% CI: 0.83;0.90) for wrist fractures.

Conclusion

ICD-10 coded MOF diagnoses are valid in the NPR. Furthermore, a set of register-based criteria can be applied to qualify if the MOF fracture was incident/acute. Thus, the NPR is a valuable and reliable data source for epidemiological research on osteoporotic fractures.

Keywords:

• major osteoporotic fractures
• validity
• positive predictive value
• the Danish National Patient Register
• algorithmic search function
• epidemiology

Data Sharing Statement

Data is not available for publication as it contains personal identifiers. Data was stored at a secure server hosted at the Danish Health Data Authority.

Ethics Statement

The medical record review was approved by The Regional Council of the Region of Southern Denmark (journal number: 22/13638) and by the department heads of the involved departments at the included hospitals. The study was not a clinical trial. The researchers did at no point contact or in any other ways interact with the patients. The study complies with the Declaration of Helsinki.²⁴

Acknowledgments

Thanks to radiographers Benjamin Bakke Hansen and Pernille Aagaard Nielsen for assessing eligible imaging studies for MOF fracture sites and contributing with the corresponding administrative coding.

Disclosure

MKS reports institutional research grants from UCB/Amgen and Region Zealand Health Scientific Research Foundation; educational grant from UCB; personal speaker fees from UCB Nordic; PhD scholarship from the Faculty of Health Sciences, University of Southern Denmark. JS received grants from Abbott Rapid Diagnostics, Novo Nordisk and Astra Zeneca. BA reports personal speaker fees from Amgen and UCB; personal speaker fees from Gedeon Richter; institutional research grants and personal consulting or speaker fees from UCB, Novartis, Pharmacosmos and Kyowa-Kirin. The authors report no other conflicts of interest in this work.

Additional information

Funding

This work was supported by the Region of Southern Denmark’s funds for independent and strategic research.