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Validity of hospital discharge data for identifying infants with cardiac defects
Barbara Kathleen Frohnert1, Richard Charles Lussky, Maureen Anne Alms
1CDC/CSTE Applied Epidemiology Fellow, Minnesota Department of Health, St. Paul, MN 55164-0975, USA.
Insights
International Classification of Diseases, 9th Edition, Clinical Modification (ICD-9-CM) codes in hospital discharge data identified most infants with cardiac defects, but accuracy was limited, with many false positives.
Area of Science:
- Pediatric Cardiology
- Health Informatics
- Public Health Surveillance
Background:
- Accurate identification of congenital heart defects (CHDs) in infants is crucial for surveillance and clinical management.
- Hospital discharge data, often coded using ICD-9-CM, is a common source for epidemiological studies.
- The validity of ICD-9-CM codes for identifying infants with cardiac defects requires careful examination.
Purpose of the Study:
- To assess the accuracy and reliability of ICD-9-CM codes in hospital discharge data for identifying infants with cardiac defects.
- To evaluate the performance of ICD-9-CM codes against established surveillance guidelines for cardiac defects.
Main Methods:
- A retrospective review of medical records for infants born in 2001 at a Minneapolis hospital.
- Infants were initially identified using ICD-9-CM codes from discharge data and keywords in medical records.
- Physician review was conducted to confirm the presence and type of cardiac defects.
Main Results:
- Out of 2,697 infants, 66 were initially identified with cardiac defects via ICD-9-CM codes; physician review confirmed 24.
- Only 41.2% of the ICD-9-CM codes accurately represented the diagnosed cardiac defects.
- The sensitivity of ICD-9-CM codes was 0.857, but the positive predictive value was only 0.364.
Conclusions:
- ICD-9-CM codes can identify a majority of infants with cardiac defects in hospital discharge data.
- However, a significant proportion of these codes represent false positives, indicating limited specificity.
- The accuracy of ICD-9-CM codes is insufficient for precise identification of specific cardiac defects in infants.
Objective:
To examine validity of the International Classification of Diseases, 9th Edition, Clinical Modification (ICD-9-CM) codes in discharge data for identifying infants with cardiac defects according to surveillance guidelines.
Study Design:
Retrospective medical record review of infants born in 2001 at one hospital in Minneapolis, Minnesota. Infants were identified using ICD-9-CM codes from hospital discharge data, and keywords in medical records.
Results:
Of 2,697 children, ICD-9-CM codes identified 66 infants coded with cardiac defects; physician review confirmed 24 had cardiac defects. Only 35 of 85 (41.2%) ICD-9-CM codes accurately reflected the cardiac defect diagnoses. Additional case finding located four infants with five cardiac defects. Sensitivity of ICD-9-CM codes for identifying these infants was 0.857, predictive value positive was 0.364.
Conclusions:
ICD-9-CM codes from hospital discharge data identified most infants with cardiac defects, but many were false positives. ICD-9-CM codes were inaccurate for specific cardiac defects.
