Table 3.

Comparison of expected and observed frequencies of fractures according to NOF thresholds.

	Hip fracture		MOP fracture
	FRAX+BMD	FRAX-BMD	FRAX+BMD	FRAX-BMD
Obese
High risk	24/38	32/43	51/51	58/54
Low risk	9/22	11/19	107/106	115/113
PPV	0.12	0.09	0.26	0.30
NPV	0.97	0.97	0.88	0.87
Sensitivity	0.63	0.69	0.32	0.31
Specificity	0.72	0.59	0.88	0.87
Non-obese
High risk	258/341	350/374	495/445	617/492
Low risk	33/59	30/44	419/398	411/386
PPV	0.13	0.10	0.30	0.26
NPV	0.97	0.97	0.87	0.86
Sensitivity	0.85	0.89	0.53	0.56
Specificity	0.47	0.31	0.71	0.63

The figures are shown as predicted counts/observed counts

For hip fracture high risk is classified as a 10-yr fracture probability ≥ 3%

For MOP fracture high risk is classified as a 10-yr fracture probability ≥ 20%

NPV – negative predictive value; PPV – positive predictive value