Table 2.
Subgroup analysis of the source of heterogeneity of included studies
| factor | number of studies |
sample size |
number of cases |
heterogeneity [I2] % (p-value) |
pooled prevalence % (95%CI) |
Q | p |
|---|---|---|---|---|---|---|---|
| publication year | |||||||
| 1998~2005 | 8 | 1227 | 353 | 93.9 (<0.001) | 29.1 (18.7, 42.3) | 0.005 | 0.941 |
| 2006~2014 | 7 | 2465 | 836 | 91.8 (<0.001) | 29.7 (23.3, 37.0) | ||
| region | |||||||
| mainland China | 13 | 2230 | 1010 | 93.5 (<0.001) | 26.9 (20.8, 34.0) | 5.477 | 0.019 |
| Taiwan, China | 2 | 462 | 179 | 82.7 (0.003) | 43.1 (31.4, 55.7) | ||
| type of treatment | |||||||
| compulsory | 6 | 1913 | 665 | 94.4 (<0.001) | 30.3 (21.5, 40.9) | 0.033 | 0.856 |
| voluntary | 11 | 1779 | 524 | 92.0 (<0.001) | 29.1 (21.3, 38.5) | ||
| diagnostic system | |||||||
| DSM-III-R~IV | 13 | 3264 | 1158 | 87.8 (<0.001) | 34.2 (29.2, 39.6) | 14.161 | <0.001 |
| CCMD-2-R | 2 | 428 | 31 | 76.2 (0.040) | 5.9 (2.1, 15.5) | ||
| mean age (year)b | |||||||
| 26.4~30.1 | 7 | 882 | 260 | 93.1 (<0.001) | 31.1 (19.6, 45.5) | 0.030 | 0.863 |
| 30.8~38.1 | 8 | 2682 | 925 | 91.9 (<0.001) | 32.4 (25.9, 39.6) | ||
| diagnostic procedure | |||||||
| one-stage | 12 | 2877 | 1066 | 82.7 (<0.001) | 35.4 (30.7, 40.4) | 13.448 | <0.001 |
| two-stage | 3 | 815 | 123 | 88.5 (<0.001) | 14.5 (8.6, 23.4) | ||
| sample size | |||||||
| 30~93 | 6 | 420 | 163 | 63.7 (<0.001) | 39.2 (31.3, 47.8) | 6.059 | 0.014 |
| 100~882 | 11 | 3272 | 1026 | 95.0 (<0.001) | 25.4 (19.0, 33.1) | ||
| sampling method | |||||||
| consecutive or random sampling | 6 | 2197 | 850 | 62.6 (0.009) | 38.2 (34.3, 42.3) | 6.483 | 0.011 |
| convenience sampling | 9 | 1495 | 339 | 94.6 (<0.001) | 22.1 (13.7, 33.5) | ||
| participation rate (%) | |||||||
| 72.7~99.0 | 4 | 1993 | 724 | 89.2 (<0.001) | 33.6 (26.9, 41.0) | 0.949 | 0.330 |
| not reported | 11 | 1699 | 465 | 93.6 (<0.001) | 27.6 (19.3, 37.9) | ||
| use of assessment tools | |||||||
| yes | 14 | 3564 | 1185 | 92.1 (<0.001) | 31.9 (26.2, 38.1) | 25.233 | <0.001 |
| no | 1 | 128 | 4 | --- | 3.1 (1.2, 8.0) | ||
| assessment tool | |||||||
| SCID-II | 7 | 1861 | 749 | 67.1 (0.002) | 39.7 (35.1, 44.4) | 7.313 | 0.007 |
| othersa | 7 | 1703 | 436 | 94.3 (<0.001) | 23.3 (15.2, 33.9) | ||
| validity/reliability of assessment tool | |||||||
| acceptable | 13 | 3347 | 1153 | 90.7 (<0.001) | 33.4 (27.8, 39.5) | 20.730 | <0.001 |
| not reported | 4 | 647 | 100 | 90.8 (<0.001) | 19.0 (10.0, 33.1) | ||
| inter-rater reliability of coders | |||||||
| yes | 9 | 2715 | 1018 | 86.1 (<0.001) | 35.9 (30.6, 41.6) | 2.031 | 0.154 |
| not reported | 5 | 813 | 167 | 94.2 (<0.001) | 24.1 (13.1, 40.1) | ||
| overall quality of studyb | |||||||
| high | 2 | 1605 | 630 | 46.9 (0.152) | 39.3 (36.9, 41.7) | reference | --- |
| uncertain | 2 | 415 | 150 | 0.0 (0.401) | 36.2 (31.7, 40.9) | 0.755 | 0.385 |
| low | 11 | 1672 | 409 | 93.6 (<0.001) | 26.0 (17.7, 36.4) | 5.815 | 0.016 |
CI, confidence interval
aincludes MINI, “PSE+CCMD-2-R”, “DIGS+DSM-Ⅳ” and “PDQ4+PDI-Ⅳ”
bsee description of method of determining overall quality in the methods section