Short summary

The primary aim of this study is to establish the validity, (i.e., positive predictive value) of a code of intracerebral hemorrhage (ICH) in the Danish Stroke Register (Stroke Register) and the Danish National Patient Register (Patient Register). 

Rationale

Danish nationwide registers represent a unique resource for epidemiological studies. Although the Patient Register and the Stroke Register have been used extensively for research, only few studies have focused on the validity of ICH diagnosis codes in these registers. In this study we will assess the validity of ICH diagnoses in both registers.  The primary aim of this study is thus to establish the positive predictive value (PPV) of a code of ICH in the Danish Stroke Register (Stroke Register) and the Danish National Patient Register (Patient Register). The secondary aim is to assess the feasibility of using sparse medical record data (discharge summary and brain imaging study reports) to correctly classify ICH by type, i.e. lobar vs. non-lobar.

Description of the cohort

Among admissions to hospitals in the Region of Southern Denmark in 2010 to 2015 recorded under diagnosis of ICH in either one or both of the registries utilized (i.e., the Stroke Register and the Patient Register), we will randomly select records on adult patients (ages 18+ years) for validation. Based on predefined criteria, we will validate the ICH diagnosis based on information from medical records, and in selected cases, further evaluate the type of ICH based on brain imaging results. 

Data and biological material

Register data will be collected from two registries, the Stroke Register, and the Patient Register as described above. Predefined information will be retrieved from medical records, and, in selected cases, through inspection of brain imaging studies, as described above. 

Collaborating researchers and departments

Department of Neurology, Odense University Hospital & Clinical Research Department, Faculty of Health Sciences, University of Southern Denmark

• Professor and Consultant David Gaist
• Staff specialist Charlotte Madsen, MD
• Stine Hald, MD
• Medical student Christine Kring Nygaard
• Medical student Sabine Hey Morris

Department of Neurosurgery, Odense University Hospital

• Associate Professor and Consultant Frantz Rom Poulsen

Department of Radiology, Odense University Hospital

• Consultant Nina Nguyen

Clinical Pharmacology & Pharmacy, Odense University Hospital & University of Southern Denmark

• Associate Professor Anton Pottegård, PhD

Centro Español Investigación Farmacoepidemiológica (CEIFE), Madrid, Spain

• Director Luis Alberto García Rodríguez, MD