Chiari malformation Type I surgery in pediatric patients. Part 1: validation of an ICD-9-CM code search algorithm
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Travis R Ladner1, Jacob K Greenberg2, Nicole Guerrero3
1Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, Tennessee;
Insights
Validated International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code algorithms can identify pediatric Chiari malformation Type I (CM-I) decompression surgery. An algorithm using a primary CM-I diagnosis demonstrated high accuracy for administrative billing data analysis.
Area of Science:
- Neurosurgery
- Pediatric Surgery
- Health Informatics
Background:
- Administrative billing data offers potential for large-scale pediatric Chiari malformation Type I (CM-I) treatment outcome assessments.
- Validated International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code algorithms are essential for such studies but are lacking for pediatric CM-I surgery.
- Current algorithms are primarily validated for adult populations.
Purpose of the Study:
- To validate two ICD-9-CM code algorithms for identifying pediatric CM-I decompression surgery using hospital billing data.
- To assess the positive predictive value (PPV) and sensitivity of these algorithms in a pediatric cohort.
Main Methods:
- Retrospective analysis of hospital billing data from three academic medical centers (2001-2013).
- Algorithm 1: Any diagnosis code 348.4 (CM-I) + procedure code 01.24 (cranial decompression) or 03.09 (spinal decompression/laminectomy).
- Algorithm 2: Subset of Algorithm 1 with primary diagnosis code 348.4 (CM-I).
Main Results:
- Algorithm 1 identified 625 first-time admissions with an overall PPV of 92% for CM-I decompression.
- Algorithm 2 identified 581 admissions with a higher PPV of 97%.
- Algorithm 2 maintained high PPV (96%-98%) across centers, while Algorithm 1's PPV varied (84%-94%). Both algorithms showed very good sensitivity (89%-91%).
Conclusions:
- An ICD-9-CM algorithm requiring a primary diagnosis of CM-I is highly accurate (excellent PPV) and sensitive for identifying pediatric CM-I decompression surgery.
- These validated algorithms provide a foundation for using administrative billing data to evaluate pediatric CM-I treatment outcomes.
- This facilitates large-scale research into pediatric neurosurgical interventions.
Abstract:
OBJECTIVE Administrative billing data may facilitate large-scale assessments of treatment outcomes for pediatric Chiari malformation Type I (CM-I). Validated International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code algorithms for identifying CM-I surgery are critical prerequisites for such studies but are currently only available for adults. The objective of this study was to validate two ICD-9-CM code algorithms using hospital billing data to identify pediatric patients undergoing CM-I decompression surgery. METHODS The authors retrospectively analyzed the validity of two ICD-9-CM code algorithms for identifying pediatric CM-I decompression surgery performed at 3 academic medical centers between 2001 and 2013. Algorithm 1 included any discharge diagnosis code of 348.4 (CM-I), as well as a procedure code of 01.24 (cranial decompression) or 03.09 (spinal decompression or laminectomy). Algorithm 2 restricted this group to the subset of patients with a primary discharge diagnosis of 348.4. The positive predictive value (PPV) and sensitivity of each algorithm were calculated. RESULTS Among 625 first-time admissions identified by Algorithm 1, the overall PPV for CM-I decompression was 92%. Among the 581 admissions identified by Algorithm 2, the PPV was 97%. The PPV for Algorithm 1 was lower in one center (84%) compared with the other centers (93%-94%), whereas the PPV of Algorithm 2 remained high (96%-98%) across all subgroups. The sensitivity of Algorithms 1 (91%) and 2 (89%) was very good and remained so across subgroups (82%-97%). CONCLUSIONS An ICD-9-CM algorithm requiring a primary diagnosis of CM-I has excellent PPV and very good sensitivity for identifying CM-I decompression surgery in pediatric patients. These results establish a basis for utilizing administrative billing data to assess pediatric CM-I treatment outcomes.
