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Table 1 Patterns of error in self-reported weight and height and their relative contributions to bias in BMI determined from self-reported values.

From: Challenging the role of social norms regarding body weight as an explanation for weight, height, and BMI misreporting biases: Development and application of a new approach to examining misreporting and misclassification bias in surveys

  Total Normal Range
  N % BMID Relative Contribution to BMID N % BMID Relative Contribution to BMID
TOTAL 1942 100.0 -1.34   689 100.0 -0.49  
Accurate Weight         
   Accurate Height 389 20.0 -0.17 -2.5 194 28.2 -0.16 -9.2
   Under-reported Height 77 4.0 1.06 3.2 43 6.2 1.00 12.7
   Over-reported Height 321 16.6 -1.48 -18.3 110 16.0 -1.12 -36.5
Over-reported Weight         
   Accurate Height 92 4.7 1.42 5.0 51 7.4 1.31 19.8
   Under-reported Height 24 1.2 3.01 2.7 14 2.0 3.28 13.6
   Over-reported Height 96 4.9 0.00 0.0 52 7.5 0.15 2.3
Under-reported Weight         
   Accurate Height 418 21.5 -1.92 -30.8 113 16.4 -1.45 -48.5
   Under-reported Height 103 5.3 -0.53 -2.1 36 5.2 -0.19 -2.0
   Over-reported Height 422 21.7 -3.54 -57.3 76 11.0 -2.34 -52.7
  Overweight Obese, Classes I-III
  N % BMI D Relative Contribution to BMI D N % BMI D Relative Contribution to BMI D
TOTAL 764 100.0 -1.33   474 100.0 -2.66  
Accurate Weight         
   Accurate Height 147 19.2 -0.19 -2.7 46 9.7 -0.21 -0.8
   Under-reported Height 29 3.8 1.16 3.3 3 0.6 0.96 0.2
   Over-reported Height 149 19.5 -1.63 -23.9 56 11.8 -1.95 -8.7
Over-reported Weight         
   Accurate Height 27 3.5 1.43 3.8 13 2.7 1.89 1.9
   Under-reported Height 7 0.9 2.75 1.9 2 0.4 - -
   Over-reported Height 27 3.5 -0.22 -0.6 15 3.2 -0.23 -0.3
Under-reported Weight         
   Accurate Height 184 24.1 -1.75 -31.7 121 25.5 -2.61 -25.0
   Under-reported Height 31 4.1 -0.62 -1.9 35 7.4 -0.84 -2.3
   Over-reported Height 163 21.3 -3.00 -48.1 183 38.6 -4.53 -65.7
  1. BMID = BMISR - BMIM (calculated for each subject, reported as mean values in table).
  2. Self-reported height and weight were considered to be accurate when within ± 2.0 kg of measured weight or ± 2.0 cm of measured height.
  3. Normal Range, BMI 18.5-24.9 kg/m2; Overweight, BMI 25.0-29.9 kg/m2; Obese, Class I-III, BMI ≥ 30.0 kg/m2.
  4. Relative Contribution to BMID = [(NErrorType*MeanErrorType)/(Ntotal *Meantotal)]*100b, where b = -1 when BMID is negative and b = 1 when BMID is positive to account for the type's direction of bias.