Trends in surgical treatment of Chiari malformation Type I in the United States.
OBJECTIVE The goal of this analysis was to define temporal and geographic trends in the surgical treatment of Chiari malformation Type I (CM-I) in a large, privately insured health care network. METHODS The authors examined de-identified insurance claims data from a large, privately insured health care network of over 58 million beneficiaries throughout the United States for the period between 2001 and 2014 for all patients undergoing surgical treatment of CM-I. Using a combination of International Classification of Diseases (ICD) diagnosis codes and Current Procedural Terminology (CPT) codes, the authors identified CM-I and associated diagnoses and procedures over a 14-year period, highlighting temporal and geographic trends in the performance of CM-I decompression (CMD) surgery as well as commonly associated procedures. RESULTS There were 2434 surgical procedures performed for CMD among the beneficiaries during the 14-year interval; 34% were performed in patients younger than 20 years of age. The rate of CMD increased 51% from the first half to the second half of the study period among younger patients (p < 0.001) and increased 28% among adult patients between 20 and 65 years of age (p < 0.001). A large sex difference was noted among adult patients; 78% of adult patients undergoing CMD were female compared with only 53% of the children. Pediatric patients undergoing CMD were more likely to be white with a higher household net worth. Regional variability was identified among rates of CMD as well. The average annual rate of surgery ranged from 0.8 surgeries per 100,000 insured person-years in the Pacific census division to 2.0 surgeries per 100,000 insured person-years in the East South Central census division. CONCLUSIONS Analysis of a large nationwide health care network showed recently increasing rates of CMD in children and adults over the past 14 years.
Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
D Andrew
DA
Wilkinson
Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
Kyle
K
Johnson
Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
Hugh J L
HJ
Garton
Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
Karin M
KM
Muraszko
Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan.
Cormac O
CO
Maher
D000293:Adolescent; D000328:Adult; D000368:Aged; D001139:Arnold-Chiari Malformation / Q000453:epidemiology* / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000639:trends*; D014481:United States / Q000453:epidemiology; D055815:Young Adult
CM-I = Chiari malformation Type I; CMD = CM-I decompression; CPT = Current Procedural Terminology; Chiari malformation Type I; ICD-9-CM = International Classification of Diseases, 9th edition, Clinical Modification; prevalence; surgical treatment