Table 2.
First- and second-generation migrants, refugee status, and psychosis risk.
| Study | Diagnosis | K | n1 | n2 | Statistical value and variance | Summary statistical value+ or common size effect++ and variance | I 2 | Q |
|---|---|---|---|---|---|---|---|---|
| First- and second-generation migrants, high-quality studies | ||||||||
| Selten et al. | NAP | 15 | 4,896 | 18,040 | RR = 2.15 (1.95–2.37)* | d = 0.42 (0.37–0.48) | 94.7 | |
| Henssler et al. | NAP | 25 | RR = 1.81 (1.62–2.02) | d = 0.33 (0.27 −0.39) | 97.6 | |||
| Cantor-Gr et al. | SCZ | 50 | 3,092 | 27,130 | RR = 2.90 (2.50–3.40) | d = 0.59 (0.51–0.68) | 68.3** | |
| Total | d = 0.44 (0.11–0.77) | 91.8 | 24.5*** | |||||
| First-generation migrants | ||||||||
| Selten et al. | PD | 29 | 14,351 | 84,701 | RR = 2.55 (2.31–2.82) | d = 0.52 (0.46–0.57) | 97.9 | |
| Henssler et al. | NAP | 20 | RR = 1.81 (1.59–2.07) | d = 0.33 (0.26–0.40) | 97.6 | |||
| Cantor-Gr. et al. | SCZ | 40 | 2,846 | 26,785 | RR = 2.7 (2.3–3.2) | d = 0.55 (0.46–0.64) | 55.4** | |
| Bourque et al. | PD | 61 | 5,556 | 33,160 | IRR = 2.3 (2.0–2.7) | d = 0.46 (0.38–0.55) | 94.4 | 1071.0*** |
| Total | d = 0.46 (0.37–0.56) | 85.2 | 20.3*** | |||||
| Second-generation migrants | ||||||||
| Selten et al. | PD | 13 | RR = 1.78 (1.66–1.90)*** | d = 0.32 (0.28–0.35) | 94.2 | |||
| Henssler et al. | NAP | 13 | RR = 1.82 (1.66–1.99) | d = 0.33 (0.28–0.38) | 90.5 | |||
| Cantor-Gr. et al. | SCZ | 7 | 474 | 8,895 | RR = 4.5 (1.5–13.1) | d = 0.82 (0.22–1.42) | 4.5 | 55.4 |
| Bourque et al. | PD | 28 | 4,515 | 24,360 | IRR = 2.1 (1.8–2.5) | d = 0.41 (0.32–0.51) | 91.1 | 303.0*** |
| Total | d = 0.34 (0.29–0.40) | 53.4 | 6.4* | |||||
| Refugees | ||||||||
| Brandt et al. | NAP | 10 | RR = 2.52 (1.78–3.57)**** | d = 0.51 (0.32–0.70) | 98.0 | |||
| Selten et al. | NAP | 4 | RR = 1.88 (1.57–2.24) | D = 0.35 (0.25–0.45) | 91.4 | |||
| Total | D = 0.41 (0.25–0.56) | 54.6 | 2.20* | |||||
Summary effects and qualitative review of included meta-analyses. PD, psychotic disorder; NAP, non-affective psychosis; SCZ, schizophrenia. K, number of effect sizes; n1, number of cases; n2, number of controls RR, risk ratio; IRR, incidence rate ratio; d, Cohen's d; +pooled result of several meta-analyses written in bold letters; ++one meta-analysis available, result converted in common effect size and presented qualitatively; Q, Cochran's Q heterogeneity statistics; I2, I2 index for heterogeneity. *p < 0.3; **p < 0.05; ***p < 0.01; ****p < 0.001.