. 2018 Jun 20;21(2):182–189. doi: 10.4048/jbc.2018.21.2.182

Table 4. Changes in femur/spine BMD compared to the baseline in the intention-to-treat population during letrozole treatment.

BMD	Baseline^*		Months		p-value
BMD	Baseline^*	12	24	36	p-value
Femur BMD
Total
N	891	751	645	288	< 0.0001^†
Mean	−0.21	−0.38	−0.52	−0.46	< 0.0001^‡
SD	1.07	1.09	1.03	0.93	0.0031^§
p-value^II	-	< 0.0001	< 0.0001	< 0.0001
Calcium	-
N	165	144	134	52	0.3707^¶
Mean	−0.49	−0.66	−0.88	−0.69	< 0.0001^**
SD	1.12	1.13	1.02	0.97	0.0066^§
p-value^II	-	< 0.0001	< 0.0001	0.0001
Non-calcium
N	726	607	511	236	< 0.0001^‡
Mean	−0.14	−0.32	−0.43	−0.41
SD	1.05	1.07	1.02	0.92
p-value^II	-	< 0.0001	< 0.0001	< 0.0001
Spine BMD
Total
N	887	752	644	286	< 0.0001^‡
Mean	−0.44	−0.76	−0.92	−0.84	< 0.0001^‡
SD	1.16	1.21	1.13	1.06	< 0.0001^§
p-value^II	-	< 0.0001	< 0.0001	< 0.0001
Calcium
N	162	145	134	51	0.1060^¶
Mean	−0.79	−1.09	−1.36	−1.25	< 0.0001^**
SD	1.06	1.10	0.97	1.00	0.0010^§
p-value^II	-	< 0.0001	< 0.0001	0.0001
Non-calcium
N	725	607	510	235	< 0.0001^§
Mean	−0.36	−0.69	−0.81	−0.75
SD	1.17	1.23	1.14	1.05
p-value^II	-	< 0.0001	< 0.0001	0.0001

BMD=bone mineral density; SD=standard deviation.

^*p=0.0001 for equality of mean baseline femur/spine BMD between the calcium and non-calcium groups using the Student t-test; ^†For equality of mean femur/spine BMD across visits using the generalized estimating equation (GEE); ^‡For a linear trend test of mean femur/spine BMD across visits using GEE analysis; ^§For a quadratic trend test of mean femur/spine BMD across visits using GEE analysis; ^∥For comparisons of mean femur/spine BMD changes between baseline and each follow-up visit using contrasts within the GEE; ^¶For an interaction effect between the calcium/non-calcium group and visits using the GEE; ^**For overall equality of mean femur/spine BMD between the calcium and non-calcium groups using the GEE.