title: Comparing US paediatric and adult weight classification at the transition from late teenage to young adulthood.
abstract: BACKGROUND
  Although paediatric growth charts are recommended for weight assessment prior to age 20, many teenagers transition earlier to adult care where absolute body mass index (BMI) is used. This study examines concordance of weight classification in older teenagers using paediatric percentiles and adult thresholds.
  
  
  METHODS
  BMI from 23 640 US teens ages 18-19 years were classified using paediatric BMI percentile criteria for underweight (< 5th), normal (5th to < 85th), overweight (85th to < 95th), obesity (≥ 95th) and severe obesity (≥ 120% × 95th percentile) and adult BMI (kg m(-2) ) criteria for underweight (< 18.5), normal (18.5-24.9), overweight (25-29.9) and obesity: class I (30-34.9), class II (35-39.9) and class III (≥ 40). Concordance was examined using the kappa (κ) statistic. Blood pressure (BP) from the same visit was classified hypertensive for BP ≥ 140/90.
  
  
  RESULTS
  The majority of visits (72.8%) occurred in adult primary care. Using paediatric/adult criteria, 3.4%/5.2% were underweight, 66.6%/58.8% normal weight, 15.7%/21.7% overweight, 14.3%/14.3% obese and 4.9%/6.0% severely/class II-III obese, respectively. Paediatric and adult classification for underweight, normal, overweight and obesity were concordant for 90.3% (weighted κ 0.87 [95% confidence interval, 0.87-0.88]). For severe obesity, BMI ≥ 120% × 95th percentile showed high agreement with BMI ≥ 35 kg m(-2) (κ 0.89 [0.88-0.91]). Normal-weight males and moderately obese females by paediatric BMI percentile criteria who were discordantly classified into higher adult weight strata had a greater proportion with hypertensive BP compared with concordantly classified counterparts.
  
  
  CONCLUSIONS
  Strong agreement exists between US paediatric BMI percentile and adult BMI classification for older teenagers. Adult BMI classification may optimize BMI tracking and risk stratification during transition from paediatric to adult care.
authors.affiliation: Department of Medicine, Kaiser Permanente Oakland Medical Center, Oakland, CA, USA.
authors.forename: B
authors.initials: B
authors.lastname: Maring
authors.affiliation: Department of Pediatrics, Kaiser Permanente San Francisco Medical Center, San Francisco, CA, USA.
authors.forename: L C
authors.initials: LC
authors.lastname: Greenspan
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Chandra
authors.affiliation: Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Daniels
authors.affiliation: Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA.
authors.forename: A
authors.initials: A
authors.lastname: Sinaiko
authors.affiliation: Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Prineas
authors.affiliation: HealthPartners Institute for Education and Research, Minneapolis, MN, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Parker
authors.affiliation: HealthPartners Institute for Education and Research, Minneapolis, MN, USA.
authors.forename: K F
authors.initials: KF
authors.lastname: Adams
authors.affiliation: Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA.|Institute for Health Research, Kaiser Permanente Colorado, Denver, CO, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Daley
authors.affiliation: HealthPartners Institute for Education and Research, Minneapolis, MN, USA.
authors.forename: N E
authors.initials: NE
authors.lastname: Sherwood
authors.affiliation: HealthPartners Institute for Education and Research, Minneapolis, MN, USA.
authors.forename: E O
authors.initials: EO
authors.lastname: Kharbanda
authors.affiliation: HealthPartners Institute for Education and Research, Minneapolis, MN, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Margolis
authors.affiliation: Institute for Health Research, Kaiser Permanente Colorado, Denver, CO, USA.|Colorado School of Public Health, University of Colorado Denver, Aurora, CO, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Magid
authors.affiliation: HealthPartners Institute for Education and Research, Minneapolis, MN, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: O'Connor
authors.affiliation: Department of Medicine, Kaiser Permanente Oakland Medical Center, Oakland, CA, USA.|Division of Research, Kaiser Permanente Northern California, Oakland, CA, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Lo
mesh_terms: D000293:Adolescent; D000328:Adult; D001794:Blood Pressure; D015992:Body Mass Index; D002648:Child; D005260:Female; D006801:Humans; D006973:Hypertension; D008297:Male; D050177:Overweight / Q000145:classification*; D010372:Pediatrics / Q000458:organization & administration*; D011320:Primary Health Care / Q000458:organization & administration*; D013851:Thinness / Q000145:classification*; D060305:Transition to Adult Care; D014481:United States; D055815:Young Adult
keywords: Adolescence; body mass index; obesity; young adult