Accuracy of Administrative Coding for Type 2 Diabetes in Children, Adolescents, and Young Adults
- Erinn T. Rhodes, MD, MPH12,
- Lori M.B. Laffel, MD, MPH123,
- Tessa V. Gonzalez, AB1 and
- David S. Ludwig, MD, PHD12
- 1Division of Endocrinology, Children’s Hospital Boston, Boston, Massachusetts
- 2Department of Pediatrics, Harvard Medical School, Boston, Massachusetts
- 3Pediatric, Adolescent, and Young Adult Section, Joslin Diabetes Center, Boston, Massachusetts
- Address correspondence and reprint requests to Erinn T. Rhodes, MD, MPH, Division of Endocrinology, Children’s Hospital Boston, 300 Longwood Ave., Boston, MA 02115. E-mail:
- ICD-9-CM, International Classification of Diseases, 9th revision, Clinical Modification
- PPV, positive predictive value
Administrative data are used with increasing frequency in research. However, validity of such data, including International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) codes (1), varies across diseases and settings (2–12). The ICD-9-CM coding for diabetes in youth may be especially susceptible to errors. While most diagnoses of diabetes in American youth are type 1 diabetes (13), incidence of type 2 diabetes is increasing (14). Rising prevalence of pediatric obesity (15) makes distinguishing between type 1 and type 2 diabetes at diagnosis difficult, and type 2 diabetes ICD-9-CM codes (250.X0/X2) include “unspecified” diabetes (1). Our aim was to evaluate the positive predictive value (PPV) of type 2 diabetes ICD-9-CM codes in children, adolescents, and young adults.
RESEARCH DESIGN AND METHODS—
In a retrospective chart review, we evaluated 432 patients aged <26 years as of 31 January 2005 with at least one visit to the Endocrine/Diabetes or Obesity Programs at Children’s Hospital Boston in Boston, Massachusetts, from 1 July 2003 to 31 January 2005 and at least one type 2 diabetes ICD-9-CM code (250.X0/X2, X = 0–9) from inpatient/outpatient sites before 5 April 2005. We identified 455 patients utilizing scheduling and billing information, and excluded 23 patients without completed visits.
To contrast the accuracy of type 2 diabetes ICD-9-CM codes with type 1 diabetes ICD-9-CM codes, we reviewed charts of patients <26 years as of 31 January 2005 with at least one visit to the Endocrine/Diabetes Program from 1 July 2003 to 31 January …