Clinical Epidemiology (Oct 2017)

Accuracy of the hypospadias diagnoses and surgical treatment registrations in the Danish National Patient Register

  • Arendt LH,
  • Ernst A,
  • Lindhard MS,
  • Jønsson AA,
  • Henriksen TB,
  • Olsen J,
  • Thorup J,
  • Olsen LH,
  • Ramlau-Hansen CH

Journal volume & issue
Vol. Volume 9
pp. 483 – 489

Abstract

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Linn Håkonsen Arendt,1,2,* Andreas Ernst,1,3,* Morten Søndergaard Lindhard,2 Anne Aggerholm Jønsson,1 Tine Brink Henriksen,2 Jørn Olsen,4 Jorgen Thorup,5 L Henning Olsen,3 Cecilia Høst Ramlau-Hansen1 *These authors contributed equally to this work 1Department of Public Health, Section for Epidemiology, Aarhus University, Aarhus, Denmark; 2Department of Paediatrics and Adolescent Medicine, Aarhus University Hospital, Aarhus, Denmark; 3Department of Urology, Section for Paediatric Urology, Aarhus University Hospital, Aarhus, Denmark; 4Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 5Department of Paediatric Surgery, Rigshospitalet and Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark Purpose: The Danish National Health registers provide a valuable data source that offers unique opportunities for observational research, including studies on the congenital anomaly hypospadias. The accuracy of the diagnosis and surgical treatment registration of hypospadias in the Danish National Patient Register (DNPR) remains unknown. Patients and methods: We randomly sampled 500 patients diagnosed with hypospadias in the DNPR from January 1, 1995 to December 31, 2012. Among these, 384 patients were also registered with surgical treatment for hypospadias. Medical records were collected and reviewed independently by two investigators. Any classification disagreements were resolved by consensus. Using the medical records as the gold standard, we estimated positive predictive values (PPVs) with 95% confidence intervals (CIs) for the hypospadias diagnoses and surgical treatment registrations overall, as well as for the clinical subtypes. Results: We were able to retrieve medical records for 463 (92.6%) patients with hypospadias diagnoses and for 329 (85.7%) patients registered with surgical treatment. Presence of hypospadias was confirmed in 450 of 463 patients, yielding an overall PPV (95% CI) of 97.6% (95.8%–98.7%). For subtypes of hypospadias, the PPVs ranged between 37.5% and 72.7%. For surgical treatment of hypospadias, the overall PPV was 99.7% (97.9%–99.9%). Conclusion: The validity of the registration of hypospadias diagnoses as well as surgical treatment for hypospadias in the DNPR is overall very high. For the specific subtypes of hypospadias diagnoses codes and the specific surgical treatment codes, the PPVs are lower and cautious use is warranted. However, the DNPR remains a valuable tool for future observational research on hypospadias. Keywords: data quality, epidemiology, hospital register diagnoses, ICD-10, positive predictive value

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