Establishment of an 11-year cohort of 8733 pediatric patients hospitalized at United States free-standing children's hospitals with de novo acute lymphoblastic leukemia from health care administrative data.

TitleEstablishment of an 11-year cohort of 8733 pediatric patients hospitalized at United States free-standing children's hospitals with de novo acute lymphoblastic leukemia from health care administrative data.
Publication TypeJournal Article
Year of Publication2014
AuthorsFisher BT, Harris T, Torp K, Seif AE, Shah A, Huang YS, L Bailey C, Kersun LS, Reilly AF, Rheingold SR, Walker D, Li Y, Aplenc R
JournalMed Care
Volume52
Issue1
Paginatione1-6
Date Published2014 Jan
ISSN1537-1948
KeywordsAdolescent, Adult, Antineoplastic Agents, Child, Child, Preschool, Clinical Coding, Cohort Studies, Comparative Effectiveness Research, Female, Hospitalization, Hospitals, Pediatric, Humans, Infant, Male, Precursor Cell Lymphoblastic Leukemia-Lymphoma, United States, Young Adult
Abstract

BACKGROUND: Acute lymphoblastic leukemia (ALL) accounts for almost one quarter of pediatric cancer in the United States. Despite cooperative group therapeutic trials, there remains a paucity of large cohort data on which to conduct epidemiology and comparative effectiveness research studies.

RESEARCH DESIGN: We designed a 3-step process utilizing International Classification of Diseases-9 Clinical Modification (ICD-9) discharge diagnoses codes and chemotherapy exposure data contained in the Pediatric Health Information System administrative database to establish a cohort of children with de novo ALL. This process was validated by chart review at 1 of the pediatric centers.

RESULTS: An ALL cohort of 8733 patients was identified with a sensitivity of 88% [95% confidence interval (CI), 83%-92%] and a positive predictive value of 93% (95% CI, 89%-96%). The 30-day all cause inpatient case fatality rate using this 3-step process was 0.80% (95% CI, 0.63%-1.01%), which was significantly different than the case fatality rate of 1.40% (95% CI, 1.23%-1.60%) when ICD-9 codes alone were used.

CONCLUSIONS: This is the first report of assembly and validation of a cohort of de novo ALL patients from a database representative of free-standing children's hospitals across the United States. Our data demonstrate that the use of ICD-9 codes alone to establish cohorts will lead to substantial patient misclassification and result in biased outcome estimates. Systematic methods beyond the use of just ICD-9 codes must be used before analysis to establish accurate cohorts of patients with malignancy. A similar approach should be followed when establishing future cohorts from administrative data.

DOI10.1097/MLR.0b013e31824deff9
Alternate JournalMed Care
PubMed ID22410405
PubMed Central IDPMC3381055
Grant ListP30 CA016520 / CA / NCI NIH HHS / United States
R01 CA133881 / CA / NCI NIH HHS / United States
R01 CA133881-01 / CA / NCI NIH HHS / United States
R01 CA133881-01A2 / CA / NCI NIH HHS / United States