Table 2.
Sensitivity analysis (PI prediction interval, CI confidence interval)
| Categorical data analysis | |||||||
|---|---|---|---|---|---|---|---|
| N datasets | N stutterers/non-stutterers | Median N stutterers/non-stutterers | OR [95% CI] | p | 95% PI | I2 [95% CI] | |
| Left-handedness (forced choice) | 24 | 523/2628 | 15.5/16.5 | 1.56 [1.11; 2.20] | 0.01* | 1.01; 2.42 | 0.00% [0.00%; 44.60%] |
| Kaganovich et al. (2010) & Mohammadi and Papadatou-Pastou (2020) removed | 22 | 422/2520 | 15/ 14 | 1.88 [1.34; 2.65] | < 0.001* | 1.16; 3.06 | 0.00% [0.00%; 46.20%] |
| Left-handedness (extreme) | 16 | 1181/3938 | 57/64 | 1.24 [0.65; 2.40] | 0.49 | 0.15; 10.03 | 66.70% [43.60%; 80.30%] |
| Chrysanthis (1947) removed | 15 | 1160/2826 | 66/53 | 1.04 [0.78; 1.40] | 0.77 | 0.76; 1.43 | 0.00% [0.00%; 53.60%] |
| Mixed handedness | 16 | 1189/3942 | 57/64 | 1.12 [0.54; 2.34] | 0.74 | 0.12; 10.98 | 63.30% [37.20%; 78.60%] |
| Bryngelson (1940) removed | 15 | 1111/3864 | 47/53 | 0.96 [0.53; 1.77] | 0.90 | 0.19; 4.89 | 56.60% [22.70%; 75.60%] |
| Bryngelson (1940) & Bryngelson and Rutherford (1937) removed | 14 | 1037/3790 | 45/48 | 0.70 [0.45; 1.10] | 0.11 | 0.33; 1.50 | 12.20% [0.00%; 50.70%] |
| Non-right-handedness | 45 | 1774/8418 | 19/19 | 1.42 [1.11; 1.81] | 0.007** | 0.71; 2.80 | 28.50% [0.00%; 50.70%] |
| Bryngelson (1940) & Chrysanthis (1947) removed | 43 | 1675/7228 | 18/19 | 1.12 [0.92; 1.35] | 0.23 | 0.92; 1.36 | 0.00% [0.0%0; 35.10%] |
| Continuous data analysis | |||||||
| d [95% CI] | p | 95% PI | I2 [95% CI] | ||||
| Main Analysis | 13 | 961/8889 | 14/17 | −0.06 [− 0.18; 0.05] | 0.26 | −0.30; 0.17 | 0.00% [0.00%; 56.60%] |
| Dellatolas et al. (1990) study 2 removed | 12 | 269/922 | 15/15 | −0.004 [− 0.17; 0.16] | 0.95 | −0.27; 0.26 | 0.00% [0.00%; 58.30%] |
*Results significant for a = 0.05
**Results significant for a = 0.01