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International Classification of Diseases-9th revision coding for preeclampsia: how accurate is it?
Stacie E Geller1, Shirin Ahmed, Monique L Brown
1Department of Obstetrics and Gynecology, College of Medicine, University of Illinois, Chicago, 60612, USA. sgeller@uic.edu
Insights
The accuracy of International Classification of Diseases-9th revision codes for preeclampsia and eclampsia is variable. Reviewing medical records is essential for accurate incidence data.
Area of Science:
- Obstetrics and Gynecology
- Medical Informatics
- Public Health
Background:
- Accurate coding of obstetric conditions is crucial for epidemiological studies and healthcare management.
- Preeclampsia and eclampsia are significant causes of maternal morbidity and mortality worldwide.
- The reliability of diagnostic codes impacts the understanding of disease prevalence and outcomes.
Purpose of the Study:
- To assess the diagnostic accuracy of International Classification of Diseases-9th revision (ICD-9) codes for preeclampsia and eclampsia.
- To determine the positive predictive value (PPV) of ICD-9 codes compared to established clinical criteria.
Main Methods:
- A retrospective chart review was conducted using discharge data from the University of Illinois Medical Center at Chicago (1999-2001).
- 135 patients with ICD-9 codes for preeclampsia or eclampsia were identified.
- The American College of Obstetricians and Gynecologists (ACOG) criteria served as the gold standard for diagnosis, with chart review comparing against ICD-9 codes.
Main Results:
- The overall PPV for ICD-9 codes for preeclampsia/eclampsia was low at 54%.
- Severe preeclampsia showed a higher PPV (84.8%) compared to mild preeclampsia (45.3%) and eclampsia (41.7%).
- Clinician error was identified as the primary cause of inaccurate coding.
Conclusions:
- ICD-9 codes for preeclampsia and eclampsia exhibit significant variability in diagnostic accuracy.
- Reliance solely on ICD-9 codes may lead to misestimation of disease incidence.
- Medical record review is indispensable for accurate data collection on preeclampsia and eclampsia incidence.
Objective:
The purpose of this study was to evaluate the accuracy of the International Classification of Diseases-9th revision codes for preeclampsia and eclampsia.
Study Design:
The University of Illinois Medical Center at Chicago discharge database was used to identify 135 women from 1999 through 2001 whose disease was coded as having preeclampsia or eclampsia. With American College of Obstetrics and Gynecology criteria as the gold standard, the diagnosis that was determined through chart review was compared with the International Classification of Diseases-9th revision code that was present in the discharge database. Patients were classified as true cases if the International Classification of Diseases-9th revision code matched the American College of Obstetricians and Gynecologists diagnosis; the positive predictive value of the code was then calculated.
Results:
The overall positive predictive value for the complete sample was only 54%, but the positive predictive value for severe preeclampsia was 84.8%, which was high compared with mild preeclampsia (45.3%) and eclampsia (41.7%). Diagnostic (clinician) error was the most common reason for miscoding error.
Conclusion:
The findings suggest that International Classification of Diseases-9th revision codes for preeclampsia/eclampsia vary greatly in their accuracy of diagnosis. Therefore, a review of medical records is required when data are being gathered on the incidence of preeclampsia and eclampsia.