Evidence map›Paper›PMID 40134971›Full record

ArticleClinical epidemiology2025

Comparing Methods for Classification of Hospital Visits in the Danish National Patient Registry (DNPR): DNPR3 Versus DNPR2.

Kirsten Skjærbæk Duch, Bergur Magnussen, Flemming Skjøth, Rasmus Westermann, Lene Wohlfahrt Dreyer

Abstract read
In one paragraph

Article in Clinical epidemiology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Kirsten Skjærbæk DuchCenter of Rheumatic Research Aalborg (CERRA), Aalborg University Hospital, Aalborg, Denmark.ORCID 0000-0002-5984-5134
Bergur MagnussenCenter of Rheumatic Research Aalborg (CERRA), Aalborg University Hospital, Aalborg, Denmark.ORCID 0009-0001-0255-8310
Flemming SkjøthResearch Support Unit, Hospital Lillebaelt, University Hospitals of Southern Denmark, Vejle, Denmark.ORCID 0000-0003-2975-647X
Rasmus WestermannCenter of Rheumatic Research Aalborg (CERRA), Aalborg University Hospital, Aalborg, Denmark.ORCID 0000-0002-8148-9658
Lene Wohlfahrt DreyerCenter of Rheumatic Research Aalborg (CERRA), Aalborg University Hospital, Aalborg, Denmark.ORCID 0000-0002-5156-2922

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: The Danish National Patient Registry (DNPR) is a central source of information on hospital contacts for the Danish population and is a key data source for health-related Danish registry studies. The data structure of DNPR was updated from DNPR2 to DNPR3 in 2019, where a key patient-type variable for classification of inpatient, outpatient, or emergency wards was removed. This affects how hospital contacts can be defined and compared across different calendar years. Aim: To present and compare different algorithms to determine the type of hospital visit (inpatient, outpatient, or emergency) for all hospital visits in Denmark from 2006 to 2021 across DNPR2 and DNPR3. Methods: The monthly number of hospital visits per 1000 citizens was presented for four different algorithms: 1) a validated approach suggested by Skjøth et al, 2) an approach suggested by the Danish Ministry of Health and Elderly, 3) the latter combined with patient type variables available in DNPR2 only, and 4) a consensus-driven algorithm introduced by Gregersen et al. Results: Using the same algorithm for DNPR2 and DNPR3 yielded the most similar results across calendar years. The least variation across calendar years was observed for the approach suggested by the Danish Ministry of Health and Elderly, whereas the validated approach suggested by Skjøth et al was more in line with the patient-type variable previously used in DNPR2. When comparing the algorithms, the main difference in the number of hospital visits was observed for inpatient and emergency visits. Conclusion: We recommend using the same algorithm across DNPR2 and DNPR3. The choice of algorithm should be based on the disease or patient group being studied and by considering how the approaches reflect reality and need in the actual study. We recommend the algorithm suggested by Skjøth et al for the specific clinical situations presented in this study.

Indexed as

admissionsclassification of hospital staysDanish National Patient RegistryDNPRLPRregistry studies

Identifiers

PMID40134971
PMCPMC11934881

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.