Skip to main content

Table 2 Reclassification and conventional statistics for measuring change in FRAX® model performance with the addition of a new simulated risk factor

From: Measuring improvement in fracture risk prediction for a new risk factor: a simulation

Statistic

RRa

1.25

1.5

1.75

2.0

2.25

2.5

2.75

3.0

3.25

3.5

NRI

0.018

0.028

0.037

0.042

0.034

0.026

0.017

0.007

− 0.003

− 0.015

IDI

0.005

0.009

0.014

0.019

0.023

0.028

0.033

0.037

0.042

0.046

ΔAUROC

− 0.004

− 0.011

− 0.019

− 0.027

− 0.035

− 0.042

− 0.049

− 0.055

− 0.060

− 0.064

ΔCalibration

− 0.076

− 0.141

− 0.198

− 0.248

− 0.291

− 0.330

− 0.365

− 0.396

− 0.424

− 0.450

Statistic

Prevalence (%)b

10

20

30

40

50

60

70

80

90

100

NRI

0.015

0.025

0.037

0.048

0.063

0.073

0.085

0.098

0.107

0.120

IDI

0.006

0.010

0.017

0.022

0.029

0.036

0.042

0.048

0.053

0.058

ΔAUROC

− 0.010

− 0.020

− 0.025

− 0.029

− 0.029

− 0.026

− 0.021

− 0.015

− 0.009

0.000

ΔCalibration

− 0.090

− 0.165

− 0.228

− 0.283

− 0.330

− 0.371

− 0.408

− 0.440

− 0.469

− 0.495

Statistic

Intervention threshold (%)c

5

10

15

20

25

30

35

40

45

50

NRI

− 0.041

− 0.074

− 0.004

0.042

0.050

0.060

0.063

0.057

0.050

0.042

IDI

0.019

0.019

0.019

0.019

0.019

0.019

0.019

0.019

0.019

0.019

ΔAUROC

− 0.291

− 0.291

− 0.291

− 0.291

− 0.291

− 0.291

− 0.291

− 0.291

− 0.291

− 0.291

ΔCalibration

− 0.248

− 0.248

− 0.248

− 0.248

− 0.248

− 0.248

− 0.248

− 0.248

− 0.248

− 0.248

  1. RR, relative risk; NRI, net reclassification index; IDI, integrated discrimination improvement
  2. aThe following simulation parameters were held constant: prevalence = 33% and intervention threshold = 20%
  3. bThe following simulation parameters were held constant: RR = 2.0 and intervention threshold = 20%
  4. cThe following simulation parameters were held constant: RR = 2.0 and prevalence = 33%