Table 6.

 Subgroup analyses by fracture site in randomised controlled trials of calcium supplements

Subgroup	Total				Hip				Vertebral				Forearm
	No of studies	RR (95% CI)	P value*		No of studies	RR (95% CI)	P value*		No of studies	RR (95% CI)	P value*		No of studies	RR (95% CI)	P value*
Risk of bias:
Low	4	0.96 (0.91 to 1.01)	0.03		3	1.68 (0.84 to 3.36)	0.05		4	0.89 (0.75 to 1.06)	0.37		4	0.98 (0.83 to 1.16)	0.24
Moderate/high	16	0.80 (0.69 to 0.93)			10	0.82 (0.71 to 0.94)			8	0.76 (0.56 to 1.03)			4	0.77 (0.54 to 1.11)
Treatment:
Calcium monotherapy	13	0.85 (0.73 to 0.98)	0.25		7	1.51 (0.93 to 2.48)	0.02		10	0.80 (0.64 to 1.01)	0.47		4	0.92 (0.69 to 1.23)	0.70
Co-administered CaD†	10	0.92 (0.86 to 0.99)			9	0.84 (0.74 to 0.96)			3	0.90 (0.74 to 1.09)			5	0.98 (0.86 to 1.13)
Residential status:
Community	17	0.88 (0.80 to 0.98)	0.63		11	1.10 (0.83 to 1.46)	0.03		10	0.86 (0.75 to 1.00)	0.30		8	0.96 (0.85 to 1.09)	—
Residential care	3	0.85 (0.74 to 0.98)			2	0.75 (0.62 to 0.92)			1	0.35 (0.06 to 1.93)			0	—
Calcium intake:
<800 mg/d	7	0.83 (0.73 to 0.95)	0.78		4	0.75 (0.61 to 0.91)	0.05		6	0.77 (0.55 to 1.07)	0.45		2	0.50 (0.11 to 2.18)	0.42
>800 mg/d	9	0.86 (0.74 to 0.99)			6	1.32 (0.77 to 2.26)			4	0.89 (0.75 to 1.05)			5	0.92 (0.77 to 1.09)

RR=relative risk.

*P value for interaction.

†Co-administered calcium and vitamin D.