Table 1 Selected characteristics of the studies included in this systematic review and meta-analysis
Study | Year | Areas | Case(n) | Total(n) | X-ray detective rate (%)[95%CI] | Age (year) | Study | QS | Comprehensive Preventive Measures |
|---|---|---|---|---|---|---|---|---|---|
Zhang et al. | 2005 | Heilongjiang (NE) | 270 | 1699 | 15.89(14.15,17.63) | 7–12 | Rep | 10 | 1.Changing grain; 2. Supplemental Se |
Su et al. | 2012 | Jilin (NE) | 8 | 742 | 1.08 (0.34,1.82) | 7–12 | Rep | 10 | 1.Changing grain; 2.water improvement |
Tao et al. | 2012 | Inner Mongolia (NE) | 54 | 929 | 5.81 (4.31,7.32) | 7–12 | Rep | 9 |  |
Xun et al. | 2009 | Inner Mongolia (NE) | 397 | 2281 | 17.40 (15.85,18.96) | 7–12 | Rep | 10 | 1. Changing grain; 2. Changing dietary patterns; 3.Improved economic conditions; 4. water improvement |
Xun et al. | 2007 | Inner Mongolia (NE) | 67 | 871 | 7.69 (5.92,9.46) | 7–12 | Rep | 10 | 1. Changing grain; |
Yuan et al. | 1998 | Inner Mongolia (NE) | 297 | 863 | 34.41 (31.24,37.58) | 7–13 | Rep | 9 |  |
Yuan et al. | 1998 | Inner Mongolia (NE) | 386 | 1693 | 22.80 (20.8,24.8) | 7–13 | Rep | 9 | 1. Changing grain; 2. Supplemental Se |
Liu et al. | 2001 | Inner Mongolia (NE) | 172 | 2498 | 6.89 (5.89,7.88) | 7–13 | Pro | 10 | 1. Changing grain |
Zhang et al. | 1995 | Inner Mongolia (NE) | 308 | 687 | 44.83 (41.11,48.55) | 7–12 | Rep | 10 | 1. Changing grain |
Zhou et al. | 2013 | Beijing (NE) | 25 | 2055 | 1.22 (0.74,1.69) | 7–12 | Rep | 10 | 1. Changing grain; 2. Changing dietary patterns; 3. Improved economic conditions; 4. Collective relocation |
Wang et al. | 2011 | Beijing (NE) | 576 | 5935 | 9.70 (8.95,10.46) | Â | Rep | 8 | 1. Changing dietary patterns; 2.Improved economic conditions; 3. Collective relocation |
Chen et al. | 2011 | Shandong (NE) | 41 | 3091 | 1.33 (0.92,1.73) | 7–12 | Rep | 10 | 1. Water improvement |
Yu et al. | 2011 | Henan (NE) | 17 | 1928 | 0.88 (0.46,1.30) | 7–12 | Rep | 10 | 1. Supplemental Se; 2. Changing grain |
Yu et al. | 2001 | Henan (NE) | 200 | 567 | 35.27 (31.34,39.21) | 3–7 | Pro | 8 | 1. Supplemental Se |
Yang et al. | 1994 | Henan (NE) | 4 | 155 | 2.58 (0.08, 5.08) | 7–12 | Rep | 8 | 1. Supplemental Se |
Wang et al. | 2011 | Shaanxi (NW) | 49 | 259 | 18.92 (14.15,23.69) | 7–16 | Rep | 9 | 1. Changing dietary patterns; 2. Supplemental Se; 3. Improved economic conditions |
He et al. | 2010 | Shaanxi (NW) | 32 | 355 | 9.01 (6.03,12.00) | 6–13 | Rep | 9 | 1. Changing dietary patterns; 2. Water improvement; 3. Improved economic conditions |
Xie et al. | 2010 | Shaanxi (NW) | 1 | 505 | 0.20(−0.19,0.59) | 7–12 | Pro | 10 | 1. Changing grain; 2. Water improvement; 3. Collective relocation |
Xie et al. | 2008 | Shaanxi (NW) | 2 | 610 | 0.33(−0.13, 0.78) | 7–13 | Pro | 10 | 1. Changing dietary patterns; 2. Supplemental Se; 3. Water improvement; 4. Improved economic conditions |
Lv et al. | 2009 | Shaanxi (NW) | 37 | 8747 | 0.42 (0.29, 0.56) | 7–13 | Rep | 10 | 1. Changing dietary patterns; 2. Supplemental Se; 3. Water improvement; 4. Improved economic conditions; 5. Returning farmland to forest |
Xu et al. | 2004 | Shaanxi (NW) | 69 | 3059 | 2.26 (1.73, 2.78) | 7–12 | Rep | 10 | 1. Supplemental Se; 2. Water improvement; 3. Collective relocation |
Cao et al. | 2004 | Shaanxi (NW) | 151 | 944 | 16.00 (13.66, 18.33) | 7–12 | Rep | 10 | 1. Supplemental Se |
Yang et al. | 2005 | Shaanxi (NW) | 4 | 110 | 3.64 (0.14, 7.13) | 7–12 | Rep | 9 | 1. Changing grain |
Wang et al. | 2001 | Shaanxi (NW) | 60 | 524 | 11.45 (8.72, 14.18) | 7–12 | Rep | 9 | 1. Supplemental Se |
Chen et al. | 2004 | Shaanxi (NW) | 26 | 840 | 3.09 (1.92, 4.27) | 7–12 | Rep | 10 | 1. Changing grain; 2. Supplemental Se; 3.Water improvement |
Sun et al. | 1992 | Shaanxi (NW) | 299 | 970 | 30.82 (27.92, 33.73) | 3–13 | Rep | 9 | 1. Supplemental Se |
Xu et al. | 2009 | Shaanxi (NW) | 487 | 2844 | 17.12 (15.74, 18.51) | 7–12 | Rep | 10 | 1. Supplemental Se |
Xie et al. | 2011 | Shaanxi (NW) | 38 | 2248 | 1.69 (1.16, 2.22) | 7–12 | Pro | 10 | 1. Supplemental Se |
Lv et al. | 2002 | Shaanxi (NW) | 441 | 3324 | 13.27 (12.11, 14.42) | 6–13 | Rep | 10 | 1. Supplemental Se; 2.Water improvement |
Zhang et al. | 2002 | Shaanxi (NW) | 500 | 2107 | 23.73 (21.91, 25.55) | 7–12 | Rep | 10 | 1. Supplemental Se |
Yi et al. | 2016 | Shaanxi (NW) | 6 | 1744 | 0.34 (0.07, 0.62) | 7–12 | Rep | 9 | 1. Changing grain; 2. Water improvement |
Cui et al. | 2013 | Gansu (NW) | 83 | 2254 | 3.68 (2.90, 4.46) | 7–12 | Rep | 10 | 1. Supplemental Se |
Ge et al. | 2008 | Gansu (NW) | 345 | 4367 | 7.90 (7.10, 8.70) | 7–12 | Rep | 10 | 1. Supplemental Se |
Liu et al. | 2007 | Gansu (NW) | 56 | 567 | 9.88 (7.42, 12.33) | 7–12 | Rep | 10 | 1. Supplemental Se; 2. Changing grain |
Zhang et al. | 2014 | Gansu (NW) | 31 | 1019 | 3.04 (1.99, 4.10) | 7–12 | Rep | 10 | 1. Supplemental Se |
Bai et al. | 2002 | Gansu (NW) | 484 | 802 | 60.22 (56.83, 63.61) | 3–13 | Pro | 10 | 1. Supplemental Se |
Luo et al. | 2012 | Gansu (NW) | 21 | 610 | 3.44 (2.00, 4.89) | 7–14 | Rep | 10 | 1. Supplemental Se |
Li et al. | 2004 | Qinghai (NW) | 383 | 1194 | 32.08 (29.43, 34.72) | 7–12 | Rep | 10 | 1. Supplemental Se; 2. Water improvement |
Ding et al. | 2001 | Qinghai (NW) | 566 | 1290 | 43.88 (41.68, 46.58) | 7–12 | Rep | 9 |  |
Ding et al. | 2003 | Qinghai (NW) | 291 | 1446 | 20.12 (18.06, 22.19) | 7–12 | Rep | 10 | 1. Water improvement; 2. Supplemental Se; 3. Changing dietary patterns |
Li et al. | 2006 | Qinghai (NW) | 2228 | 5122 | 43.50 (42.14, 44.86) | 7–12 | Rep | 9 | 1. Water improvement; 2. Supplemental Se |
Bao et al. | 1998 | Qinghai (NW) | 195 | 436 | 44.72 (40.06, 49.39) | 7–12 | Rep | 10 |  |
Li et al. | 2002 | Qinghai (NW) | 168 | 407 | 41.28 (36.49, 46.06) | 7–12 | Rep | 10 |  |
Zhao et al. | 2016 | Tibet (SW) | 1388 | 43,034 | 3.23 (3.06, 3.39) | 7–12 | Rep | 9 | 1. Supplemental Se; 2. Changing grain; 3. Collective relocation; 4. Improved economic conditions |
Zhao et al. | 2011 | Tibet (SW) | 15 | 431 | 3.48 (1.75, 5.21) | 7–12 | Pro | 10 |  |
Gong et al. | 2004 | Tibet (SW) | 73 | 611 | 11.95 (9.38, 14.52) | 4–12 | Pro | 10 | 1. Supplemental Se |
A et al. | 2015 | Sichuan (SW) | 182 | 14,189 | 1.28 (1.10, 1.47) | 7–12 | Rep | 10 | 1. Supplemental Se |
Wang et al. | 2005 | Sichuan (SW) | 551 | 3149 | 17.50 (16.17, 18.82) | 7–12 | Rep | 10 | 1. Supplemental Se |
Zhang et al. | 2009 | Sichuan (SW) | 24 | 1243 | 1.93 (1.17, 2.70) | 7–12 | Rep | 10 | 1. Supplemental Se; 2. Changing dietary patterns |
Li et al. | 2003 | Sichuan (SW) | 314 | 1600 | 19.63 (17.68, 21.57) | 7–12 | Rep | 10 | 1. Supplemental Se; 2. Changing dietary patterns |
Deng et al. | 2008 | Sichuan (SW) | 675 | 8689 | 7.77 (7.21, 8.33) | 7–13 | Rep | 10 | 1. Improved economic conditions; 2. Changing dietary patterns |
Hunag et al. | 2010 | Sichuan (SW) | 373 | 13,472 | 2.77 (2.49, 3.05) | 7–12 | Rep | 10 | 1. Supplemental Se; 2. Collective relocation; 3. Changing grain |
Deng et al. | 1999 | Sichuan (SW) | 569 | 2224 | 25.58 (23.77, 27.40) | 7–12 | Rep | 10 | 1. Improved economic conditions |