Table 2. Subgroup analysis for vertebral fractures and percent change of lumbar spine BMD at different time-points.
| Factor | Vertebral fractures | 6 months | 12 months | 24 months | 36 months | ||||||||||
| N | WMD[95%CI] | P | N | WMD[95%CI] | P | N | WMD[95%CI] | P | N | WMD[95%CI] | P | N | WMD[95%CI] | P | |
| M1 | 5 | 0.43[0.22,0.84] | N.S. | 6 | 4.53[2.89,6.17] | 0.05 | 8 | 4.93[3.59,6.28] | 0.01 | N.A. | N.A. | N.A. | N.A. | ||
| M2 | 5 | 0.69[0.44,0.98] | 5 | 2.73[1.99,3.48] | 11 | 2.91[2.05,3.76] | 6 | 3.64[2.59,4.69] | 4 | 5.87[4.59,7.15] | |||||
| U1 | 3 | 0.78[0.35,1.72] | N.S. | 7 | 3.46[1.96,4.96] | N.S. | 9 | 3.47[2.23,4.68] | N.S. | 4 | 4.32[2.26,6.39] | N.S. | 2 | 6.52[4.32,8.81] | N.S. |
| U2 | 7 | 0.57[0.41,0.80] | 4 | 4.02[2.56,5.48] | 10 | 3.63[2.51,4.75] | 2 | 3.34[3.02,3.65] | 2 | 6.09[5.77,6.40] | |||||
| G1 | 6 | 0.56[0.40,0.79] | N.S. | 3 | 4.51[2.83,6.18] | N.S. | 7 | 3.88[2.36,5.41] | N.S. | 1 | 3.35[3.03,3.67] | N.S. | 2 | 6.09[5.77,6.40] | N.S. |
| G2-3 | 4 | 0.77[0.38,1.59] | 8 | 3.31[2.20.4.41] | 12 | 3.57[2.59,4.55] | 5 | 3.85[2.64,5.05] | 2 | 6.52[4.32,8.81] | |||||
| Ca1 | 9 | 0.60[0.44,0.80] | N.S. | 8 | 3.65[2.46,4.84] | N.S. | 13 | 3.33[2.50,4.16] | N.S. | 2 | 3.34[3.03,3.66] | N.S. | 2 | 6.09[5.77,6.40] | N.S. |
| Ca2 | 1 | 0.73[0.13,4.09] | 3 | 3.85[2.19,5.52] | 6 | 4.61[2.84,6.83] | 4 | 4.55[2.89,6.21] | 2 | 6.52[4.32,8.81] | |||||
| RA | 2 | 1.80[0.62,5,24] | 0.03 | 3 | 3.46[2.25,4.66] | N.S. | 5 | 3.62[2.66,4.58] | N.S. | 3 | 4.30[2.75,5.85] | N.S. | 2 | 6.52[4.32,8.81] | N.S. |
| RD | 8 | 0.52[0.38,0.73] | 8 | 3.88[2.61,5.16] | 14 | 3.96[2.62,5.30] | 3 | 3.34[3.03,3.66] | 2 | 6.09[5.77,6.40] | |||||
| Age1 | 7 | 0.67[0.48,0.92] | N.S. | 8 | 3.32[2.33,4.31] | N.S. | 14 | 3.77[2.82,4.71] | N.S. | 5 | 3.40[3.09,3.71] | N.S. | 3 | 6.12[5.81,6.43] | N.S. |
| Age2 | 3 | 0.26[0.08,0.89] | 3 | 5.23[1.48,8.62] | 5 | 3.41[1.39,5.43] | 1 | 2.51[0.07,4.94] | 1 | 4.40[1.81,7.00] | |||||
| High | 9 | 0.59[0.36,0.96] | N.S. | 7 | 3.43[2.36,4.50] | N.S. | 12 | 3.93[3.16,4.70] | N.S. | 3 | 3.90[2.53,5.27] | N.S. | 3 | 5.59[3.87,7.71] | N.S. |
| Low | 1 | 0.63[0.43,0.91] | 4 | 4.15[2.33,5.98] | 7 | 2.87[1.05,4.69] | 3 | 3.35[3.04,3.67] | 1 | 6.11[5.79,6.43] | |||||
| B1 | 7 | 0.65[0.38,1.12] | N.S. | 6 | 3.31[2.20,4.43] | N.S. | 9 | 3.98[3.26,4.71] | N.S. | 2 | 4.55[2.89,6.21] | N.S. | 2 | 6.52[4.32,8.81] | N.S. |
| B2 | 3 | 0.58[0.40,0.83] | 5 | 4.32[2.85,5.19] | 10 | 3.08[1.68,4.89] | 4 | 3.34[3.03,3.66] | 2 | 6.09[5.77,6.40] | |||||
N.A.: not available, N.S.: no significant between the two group, WMD: weighted mean difference, 95%CI: 95% confidential interval.
M stands for manner, M1:prevention manner, M2:treatment manner; U stands for usage, U1: continuous therapy of BPs, U 2: intermittent therapy of BPs; G stands for generation, G1: the first generation of BPs, G2: the second and third generation of BPs; Ca stands for calcium, Ca1: supplemented with calcium, Ca2: not supplemented with calcium; RA: only RA patients were included, RD: patients with all sort of rheumatic diseases were included; in mean age, Age1 : more than 50 years, Age2: less than 50 years; in Jadad score, High: ≥3 points, Low: <3 points; B stands for blinding, B1: blinding to patients; B2: not blinding to patients.