Alendronate versus Raloxifene for Postmenopausal Women: A Meta-Analysis of Seven Head-to-Head Randomized Controlled Trials

Table 5

Subgroup analysis of the main meta-analysis comparing Aln and Rlx.

Factors	Subgroups	Risk of total fracture		LS BMD at 12 months		LS BMD at 12 months; (Absence of outlier)		Risk of upper GI disorders		Risk of upper GI disorders; (Absence of outlier)
		N	RR (95% CI)	N	WMD (95% CI)	N	WMD (95% CI)	N	RR (95% CI)	N	RR (95% CI)
	Total	6	1.19 [0.78, 1.83]	6	2.92 [2.23, 3.62]	5	2.37 [2.17, 2.58]	6	1.10 [0.77, 1.58]	5	1.30 [1.04, 1.63]
	Heterogeneity		P = 0.78; 𝐼^2 = 0%		P  <  0.01; I^2  =  95%		P = 0.19; 𝐼^2 = 35%		P  =  0.07; I^2  =  52%		P = 0.83; 𝐼^2 = 0%
Patterns of treatments in Aln	Daily	4	1.23 [0.77, 1.98]	3	2.39 [2.23, 2.56]	2	2.20 [2.03, 2.37]	3	1.34 [1.04, 1.72]	3	1.34 [1.04, 1.72]
	Weekly	2	0.86 [0.39, 1.90]	3	2.56 [2.32, 2.79]	3	2.56 [2.32, 2.79]	3	0.92 [0.49, 1.72]	2	1.21 [0.67, 2.20]
			P = 0.44		P = 0.26		P  =  0.01		P = 0.27		P = 0.76
Age	≥65	3	1.17 [0.72, 1.91]	2	3.88 [0.55, 7.22]	1	/	2	1.32 [1.01, 1.73]	2	1.32 [1.01, 1.73]
	<65	3	1.01 [0.48, 2.14]	4	2.51 [2.29, 2.73]	4	/	4	1.03 [0.61, 1.74]	3	1.26 [0.83, 1.90]
			P = 0.74		P = 0.42		/		P = 0.41		P = 0.85
Methodological quality^a	Low	2	1.39 [0.59, 3.27]	3	3.48 [1.26, 5.69]	2	2.22 [2.04, 2.39]	2	1.67 [0.67, 4.13]	2	1.67 [0.67, 4.13]
	High	4	1.05 [0.66, 1.67]	3	2.50 [2.28, 2.72]	3	2.50 [2.28, 2.72]	4	1.03 [0.68, 1.57]	3	1.28 [1.01, 1.62]
			P = 0.57		P = 0.39		P = 0.05		P = 0.35		P = 0.58
Sample size^b	≥400	5	/	3	2.40 [2.13, 2.67]	3	2.40 [2.13, 2.67]	3	0.95 [0.57, 1.58]	2	1.26 [0.99, 1.61]
	<400	1	/	3	3.49 [1.25, 5.73]	2	2.33 [1.84, 2.82]	3	1.55 [0.88, 2.77]	3	1.55 [0.88, 2.76]
			/		P = 0.34		P = 0.80		P = 0.21		P = 0.51
Funding	Aln	2	0.86 [0.39, 1.90]	2	2.55 [2.31, 2.79]	2	/	2	0.77 [0.43, 1.37]	1	/
	Rlx	2	1.17 [0.66, 2.07]	2	2.20 [1.62, 2.78]	1	/	2	1.34 [1.04, 1.74]	2	/
	None	2	1.39 [0.59, 3.27]	3	3.48 [1.26, 5.69]	3	/	2	1.67 [0.67, 4.13]	2	/
			P = 0.70		P = 0.38		/		P = 0.18		/

Aln: Alendronate; Rlx: Raloxifene; N: number of trials; WMD: weighted mean differences; CI: confidential interval; RR: risk ratios; LS: lumbar spine; BMD: bone mineral density; ALP: serum bone-specific alkaline phosphatase; AEs: adverse effects; GI: gastrointestinal.
^aResults were not changed when subgroups were divided by adequate randomization, concealing allocation, blinding, applying ITT analysis.
^bThe cutoff of sample size was defined according to a threshold rule-of-thumb.
Bold font means the statistic significances were existed.