title: Bedside estimation of patient height for calculating ideal body weight in the emergency department.
abstract: BACKGROUND
  Ideal body weight (IBW), which can be calculated using the variables of true height and sex, is important for drug dosing and ventilator settings. True height often cannot be measured in the emergency department (ED).
  
  
  OBJECTIVE
  Determine the most accurate method to estimate IBW using true height-based IBW that uses true height estimated by providers or patients compared to true height estimated by a regression formula using measured tibial length, and compare all to the conventional 70 kg male/60 kg female standard IBW.
  
  
  METHODS
  Prospective, observational, double-blind, convenience sampling of stable adult patients in a tertiary care ED from September 2004 to April 2006. Derivation set (215 patients) had blinded provider and patient true height estimates and tibial length measurements compared to gold-standard standing true height. A validation set (102 patients) then compared the accuracy of IBW using true height calculated from the regression formula vs. IBW using gold-standard true height. Regression formula for men tibial length-IBW (kg) = 25.83 + 1.11 × tibial length; for women tibial length-IBW = 7.90 + 1.20 × tibial length; R(2) = 0.89, p < 0.001. Inter-rater correlation of tibial length was 0.94.
  
  
  RESULTS
  Derivation set: percent within 5 kg of true height-based IBW for men/women =
  
  
  METHODS
  91.1%:/85.7%; Physician: 66.1%/45.1%; Nurse: 65.7%/ 47.3%; tibial length: 66.1%/63.7%; and 70 kg male/60 kg female standard 46%/75%. Validation set: tibial length-IBW estimates were within 5 kg of true height-ideal body weight in only 56.2% of men and 42.2% of women.
  
  
  CONCLUSIONS
  PATIENT-reported height is the best bedside method to estimate true height to calculate ideal body weight. Physician and nurse estimates of true height are substantially less accurate, as is true height obtained from a regression formula that uses measured tibial length. All methods were more accurate than using the conventional 70 kg male/60 kg female IBW standard.
authors.affiliation: Naval Medical Center, San Diego, California 92134, USA.
authors.forename: Christine R
authors.initials: CR
authors.lastname: Stehman
authors.forename: Robert G
authors.initials: RG
authors.lastname: Buckley
authors.forename: Frank L
authors.initials: FL
authors.lastname: Dos Santos
authors.forename: Robert H
authors.initials: RH
authors.lastname: Riffenburgh
authors.forename: Aaron
authors.initials: A
authors.lastname: Swenson
authors.forename: Sheila
authors.initials: S
authors.lastname: Mulligan
authors.forename: Nathan
authors.initials: N
authors.lastname: Mjos
authors.forename: Matt
authors.initials: M
authors.lastname: Brewer
mesh_terms: D000886:Anthropometry / Q000379:methods*; D001827:Body Height; D001835:Body Weight; D004311:Double-Blind Method; D004635:Emergency Medicine; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D011446:Prospective Studies; D013977:Tibia / Q000033:anatomy & histology*