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. 2017 Dec 6;6:243. doi: 10.1186/s13643-017-0630-4

Table 3.

Sensitivity of heterogeneity measures to accounting for effect modification when prevalence of the outcome was 30%

Two-stage approach One-stage approach
τ 2 Number of studies Strength of effect modificationa Iemod2Icrude2 Remod2Rcrude2 Iemod2Icrude2 Remod2Rcrude2
0.5 15 Weak 0.17 (1.00) 0.89 (0.38) 1.00 (0.41) 0.91 (0.25)
1.0 15 Weak 0.01 (0.57) 0.60 (0.34) 0.99 (0.07) 0.81 (0.25)
1.5 15 Weak 0.06 (0.59) 0.50 (0.30) 0.98 (0.05) 0.75 (0.18)
0.5 15 Moderate 0.02 (1.00) 0.86 (0.39) 0.56 (0.68) 0.86 (0.34)
1.0 15 Moderate 0.08 (0.87) 0.68 (0.46) 0.82 (0.28) 0.98 (0.40)
1.5 15 Moderate 0.34 (0.77) 0.65 (0.39) 0.82 (0.25) 1.06 (0.46)
0.5 15 Strong 0.01 (1.00) 0.82 (0.42) 0.11 (0.23) 0.90 (0.37)
1.0 15 Strong 0.32 (1.00) 0.81 (0.43) 0.20 (0.28) 1.07 (0.57)
1.5 15 Strong 0.42 (0.93) 0.75 (0.46) 0.22 (0.29) 1.31 (0.86)
0.5 30 Weak 0.01 (1.00) 0.78 (0.39) 1.00 (0.27) 0.88 (0.19)
1.0 30 Weak 0.01 (0.36) 0.53 (0.22) 1.00 (0.04) 0.78 (0.16)
1.5 30 Weak 0.16 (0.49) 0.47 (0.22) 0.98 (0.03) 0.74 (0.14)
0.5 30 Moderate 0.01 (1.00) 0.77 (0.40) 0.59 (0.46) 0.86 (0.29)
1.0 30 Moderate 0.01 (0.54) 0.65 (0.30) 0.82 (0.19) 0.99 (0.33)
1.5 30 Moderate 0.19 (0.61) 0.59 (0.30) 0.82 (0.17) 1.07 (0.31)
0.5 30 Strong 0.01 (1.00) 0.79 (0.37) 0.09 (0.15) 0.95 (0.37)
1.0 30 Strong 0.01 (0.68) 0.70 (0.34) 0.16 (0.17) 1.10 (0.46)
1.5 30 Strong 0.33 (0.73) 0.71 (0.33) 0.16 (0.17) 1.23 (0.69)

Median (IQR) was presented

We present the ratios of the measure estimated from a model that ignored the effect modifier to one that included the effect modifier and an interaction term between it and the treatment status

aEffect modification was classified as weak when β w=1, β xw=1, as moderate when β w=1, β xw=3, and as strong when β w=2, β xw=5