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Table 3 Optimal steps/day from ROC analysis and Colley et al. thresholds a for censored and uncensored steps by activity cut point for children and adolescents

From: Steps/day translation of the moderate-to-vigorous physical activity guideline for children and adolescents

   Children  
  Freedson 3 METS Freedson 4 METS Evenson
  Optimal Colleya Optimal Colleya Optimal Colleya
Censored       
Boys 6–11 yrs 6,500 12,000 9,500 12,000 10,500 12,000
 FP/FNb (0%/6%) (0%/68%) (17%/21%) (0%/59%) (19%/20%) (5%/39%)
 Accuracy .94 .35 .80 .56 .81 .80
 AUC .99 (.98–1.0) .91 (.88–.94) .90 (.87–.93)
Girls 6–11 yrs 6,500 12,000 9,000 12,000 10,500 12,000
 FP/FNb (0%/15%) (0%/83%) (15%/21%) (1%/74%) (21%/15%) (6%/42%)
 Accuracy .85 .19 .81 .55 .80 .86
 AUC .88 (.85–.91) .90 (.88–.93) .88 (.85–.92)
Uncensored       
Boys 6–11 yrs 8,500 12,000 12,000 12,000 13,000 12,000
 FP/FNb (9%/6%) (0%/33%) (20%/21%) (20%/21%) (26%/21%) (43%/9%)
 Accuracy .94 .68 .79 .79 .76 .72
 AUC .99 (.97–1.0) .88 (.85–.92) .86 (.83–.90)
Girls 6–11 yrs 8,500 12,000 11,500 12,000 13,500 12,000
 FP/FNb (0%/9%) (0%/48%) (24%/19%) (17%/27%) (22%/27%) (42%/11%)
 Accuracy .91 .53 .79 .77 .77 .65
 AUC .97 (.95–1.0) .87 (.84–.90) .84 (.80–.89)
   Adolescents  
  Freedson 3 METS Freedson 4 METS Evenson
  Optimal Colley a Optimal Colley a Optimal Colley a
Censored       
Boys 12–17 yrs 8,500 12,000 11,500 12,000 10,500 12,000
 FP/FNb (21%/21%) (1%/68%) (11%/14%) (8%/22%) (15%/21%) (3%/34%)
 Accuracy .79 .61 .88 .90 .83 .90
 AUC .99 (.97–1.0) .93 (.91–.96) .93 (.91–.95)
Girls 12–17 yrs 7,500 12,000 9,000 12,000 9,500 12,000
 FP/FNb (23%/16%) (0%/82%) (18%/19%) (4%/52%) (12%/13%) (2%/41%)
 Accuracy .79 .78 .82 .95 .88 .95
 AUC .88 (.86–.91) .87 (.78–.96) .93 (.88–.98)
Uncensored       
Boys 12–17 yrs 11,000 12,000 14,000 12,000 13,000 12,000
 FP/FNb (28%/24%) (16%/38%) (15%/17%) (34%/6%) (21%/19%) (29%/13%)
 Accuracy .74 .72 .84 .70 .80 .75
 AUC .84 (.82–.87) .91 (.88–.94) .89 (.87–.92)
Girls 12–17 yrs 10,500 12,000 11,500 12,000 12,000 12,000
 FP/FNb (24%/24%) (9%/52%) (23%/19%) (19%/24%) (17%/18%) (17%/18%)
 Accuracy .76 .79 .77 .81 .83 .83
 AUC .85 (.81–.88) .84 (.73–.95) .90 (.83–.96)
  1. a Colley et al. thresholds are 12,000 steps/day across gender and age groups.
  2. bFP/FN is false positives and false negatives.
  3. Accuracy = (true positives + true negatives)/(true positives + true negatives + false positives + false negatives).
  4. AUC = area under the curve.