Table 4 Osteoporosis classification results at 95% PPV and 95% NPV thresholds on Hologic testing data.

From: Automated bone mineral density prediction and fracture risk assessment using plain radiographs via deep learning

Threshold with high PPV ≥95%

 

Hip

Spine

Threshold BMD (g/cm2), T-score (T1)

0.513, −2.9

−3.0*

PPV for osteoporosis

  

TP/(TP + FP), n/N

524/549

4750/5030

PPV (95% CI)

95.5 (93.5–96.8)

94.4 (93.8–95.0)

PPV for 10-year major fracture risk ≥20%

 

NA

TP/(TP + FP), n/N

230/283

 

PPV (%, 95% CI)

81.3 (76.9–85.0)

 

PPV for 10-year hip fracture risk ≥3%

 

NA

TP/(TP + FP), n/N

492/498

 

PPV (95% CI)

98.8 (97.4–99.5)

 

Threshold with high NPV ≥95%

Threshold BMD (g/cm2), T-score (T2)

0.580, −2.3

−2.1*

NPV for osteoporosis

  

TN/(TN + FN), n/N

3812/4008

7418/7765

NPV (95% CI)

95.1 (94.5–95.6)

95.5 (95.1–96.0)

NPV for 10-year major fracture risk ≥20%

 

NA

TN/(TN + FN), n/N

3884/3953

 

NPV (95% CI)

98.3 (97.8–98.6)

 

NPV for 10-year hip fracture risk ≥3%

 

NA

TN/(TN + FN), n/N

2575/2839

 

NPV (95% CI)

90.7 (89.8–91.5)

 

Prediction categorization

Patient number (%)

  

Predicted BMD or T-score <T1

549 (10.6)

5030 (27.7)

T1 ≤ predicted BMD or T-score <T2

607 (11.8)

5380 (29.6)

Predicted BMD or T-score ≥T2

4008 (77.6)

7765 (42.7)

  1. FN false negative, FP false positive, NA not available, NPV negative predictive value, PPV positive predictive value, TN true negative, TP true positive.
  2. *Based on the vertebrae with the lowest T-score.