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Table 8 Sensitivity, specificity and positive predictive value of self-reported data and correction equations for weight status

From: Measuring the bias, precision, accuracy, and validity of self-reported height and weight in assessing overweight and obesity status among adolescents using a surveillance system

Grade Weight Status1 Sensitivity2 Specificity3 Positive Predictive Value4
   Girls Boys All Girls Boys All Girls Boys All
Self-Reported
8th Overweight 58.2% 62.7% 60.5% 91.2% 87.5% 89.2% 60.1% 51.6% 55.3%
  Obese 66.8% 73.6% 70.8% 97.7% 96.4% 97.0% 84.0% 83.0% 83.4%
  Overweight/Obese 77.2% 84.6% 81.3% 93.9% 88.5% 91.1% 86.7% 81.2% 83.4%
11th Overweight 64.1% 60.4% 62.0% 95.2% 92.7% 93.9% 71.1% 63.8% 66.9%
  Obese 76.3% 85.0% 81.9% 98.9% 97.5% 98.1% 89.8% 88.7% 89.1%
  Overweight/Obese 81.4% 84.2% 83.1% 97.5% 93.6% 95.6% 92.5% 88.4% 89.9%
Correction Equations
8th Overweight 67.4% 62.5% 64.8% 86.8% 86.9% 86.9% 54.0% 50.2% 52.1%
  Obese 73.4% 80.2% 77.4% 97.1% 96.5% 96.8% 82.0% 84.7% 83.7%
  Overweight/Obese 86.0% 86.3% 86.1% 88.2% 86.9% 87.5% 78.9% 79.4% 79.2%
11th Overweight 72.0% 69.6% 70.7% 91.2% 90.6% 90.9% 59.9% 61.2% 60.6%
  Obese 82.4% 85.5% 84.4% 99.0% 97.2% 98.1% 91.4% 87.8% 89.0%
  Overweight/Obese 85.9% 89.7% 88.2% 92.0% 91.1% 91.5% 80.1% 85.2% 83.2%
  1. [1] Using the U.S. Centers for Disease Control and Prevention (CDC) sex and age BMI growth charts, we classified students into underweight/normal (<85th percentile), overweight (≥85th percentile to <95th percentile) and obese (≥95th percentile) weight status categories
  2. [2] Sensitivity: proportion of the weight status category correctly classified by self-reported measurements in that weight status category
  3. [3] Specificity: proportion of students who were not in the weigh status category as correctly classified as not in that weight status category by self-reported measurements.
  4. [4] Positive predictive value: proportion of students identified by self-reported measures with a particular weight status that are truly in such particular weight status