Predicted effects and cost of different strategies for preventing fracture in US white women with osteoporosis or osteopenia diagnosed by bone densitometry at hip or spine (mean age 72 years at baseline) and treated for 8.5 years (hip) and 3.7 years (spine)*

	Treatment strategy and site of measurement
	Basic cohort*		Treat if T score ≤ −2.5			Treat if T score ≤−1.5			Treat all
	Hip	Spine	Hip	Spine	Hip	Spine	Hip		Spine
No of women	8047	6892		1424	2274		3871	4108		8047		6892
% of population	100	100		17.7	33		48.1	59.6		100		100
No of fractures in untreated women:
Any non-spine	2044	—		580	—		782	—		2044		—
Hip	622	—		253	—		371	—		622		—
Spine	389	361		149	213		191	230		389		361
No of fractures prevented by treatment†(% of fractures in basic cohort):
Any non-spine	—	—		290 (14)	—		379 (19)	—		505 (25)		—
Hip	—	—		127 (20)	—		179 (29)	—		204 (33)		—
Spine	—	—		75 (19)	107 (29)		93 (24)	114 (32)		113 (29)		127 (35)
Total cost of treatment ($m)‡	—	—		7.3	5.0		19.7	9.1		41.0		15.3
Cost ($)/prevented fracture:
Any non-spine	—	—		25 043	—		52 090	—		81 267		—
Hip	—	—		57 184	—		110 291	—		201 175		—
Spine	—	—		96 832	47 180		212 281	79 998		363 183		120 474

*Data derived from Stone et al¹¹

† Assuming a best case scenario in which risk is reduced by 50% for all fractures in women with a T score below −2.5, by 44% for hip fracture and 20% for spine fracture in women with T score of −2.5 to −1.5, and by an estimated (in absence of data) 10% for women with a T score above −1.5.^{15 16}

‡Based on an estimate of annual drug costs of $600 per patient with no costs attributed to bone densitometry, monitoring of treatment efficacy, or treating possible adverse events.