Table 1.
Information extracted from articles entered into the meta-analysis process
| Author | Year of study | City of study | Age | Type of study | Overall IQ (mean) | Overall IQ (SD) | Sample size |
|---|---|---|---|---|---|---|---|
| Bezorgyan[13] | 2012 | Yasouj | 28.08 | - | 79.42 | 8.55 | 100 |
| Rahimian Bugar[15] | 2009 | Semnan | 9-11 | Causal-comparative | 94.05 | 16.11 | 90 |
| Sharifi[16] | 2007 | Chaharmahal va bakhtyari | 6-15 | Causal-comparative | 89.56 | 11.68 | 104 |
| Sheykh Mounesi[17] | 2008 | Mazandaran | - | Causal-comparative | 100.87 | 13 | 80 |
| Mehry Nejad[18] | 2006 | Tehran | <11 | - | 107.63 | 9.54 | 500 |
| Araghizade[7] | 2005 | Tehran | >40 | - | - | - | 64 |
| Fathi Ashtiani[14] | 1999 | Tehran | 9 | - | - | - | 60 |
| Ebrahimi[19] | 2000 | Isfahan | >40 | - | 82.29 | 19.02 | 80 |
| Bagheri[20] | 2000 | Tabriz | 7 | Causal-comparative | - | - | 240 |
| Soleymani[21] | 2011 | Tehran | 4-6.5 | Association study | 108.24 | 9.45 | 42 |
| Tavakoli[22] | 2007 | Isfahan | 27 | Association study | 88.06 | - | 29 |
| Razavi[23] | 2010-2011 | Neyshabur | 5-6.5 | Descriptive-analytical | - | - | 80 |
| Alizade[24] | 2015-2016 | Isfahan | 7-15 | Before-after study | 98.85 | 13.65 | 27 |
| Soghraei Karbalaei[25] | 2016 | Systan and Baluchestan | 12-18 | Descriptive-analytical | 79 | 6 | 86 |
| Ghasem Tabar[26] | 2015 | Tehran | 5 | Before-after study | - | - | 30 |
| Nasri[27] | 2013-2014 | Rasht | 8 | Before-after study | 96.9 | 4.01 | 60 |
| Atadokht[28] | 2012-2013 | Ardebil | 7-11 | Causal-comparative | 98.33 | 11.01 | 100 |
| Manshaei[29] | 2012-2013 | Isfahan | 6-12 | Causal-comparative | - | - | 90 |
| Dalvand[30] | 2008 | Tehran | 4-8 | Semi-experimental | 93 | 2.47 | 20 |
| Mahreyar[31] | 2002 | Shiraz | - | Causal-comparative | 95.39 | 12.84 | 236 |
| Mahram[32] | 2003 | Zanjan | 7.3 | Historical cohort | 89.26 | 9.96 | 126 |
| Sadeghi Poor[33] | 2001 | Tehran | 4-13 | Historical cohort | 111.48 | 10 | 191 |
| Azizi[34] | 2005 | Tehran | 4-7 | Historical cohort | 103 | 13.07 | 82 |
| Nasiri Amiri[35] | 2004-2007 | Babol | 6-7 | Prospective cohort | 95.43 | 14.41 | 120 |
| Yasseri[36] | 2005 | - | 25-45 | - | 109.35 | 52 | |
| Shiri Aminloo[37] | 2012-2013 | - | 6-12 | - | 99.03 | 11.53 | 298 |
| Yaghoubi[38] | 2007 | Tehran | - | Semi-experimental | 108.75 | 6.2 | 16 |
| Mahmoodi Rad[39] | 2007 | Tehran | 9 | Before-after study | 92.4 | 8.05 | 48 |
| Khoshouei[40] | 2010-2011 | Isfahan | 6-7 | Comparative | - | - | 50 |
| Ashuri[41] | 2009-2010 | Tehran | 13-17 | Before-after study | 64.65 | 2.91 | 20 |
| Hashemi[42] | 2008-2009 | Fars | 6-9 | Semi-experimental | 85.6 | 9.08 | 23 |
| Abdi[43] | 2011 | Tehran | 30-50 | - | 102.5 | 4.67 | 50 |
| Alipour[1] | 2011 | Tehran | - | Descriptive | 28.53 | 2.97 | 120 |
| Rezaei[44] | 2010-2011 | Tabriz | 22.1 | Descriptive | 165.92 | 28.31 | 315 |
| Jabbari[45] | 2001 | Shiraz | 10-12 | Comparative | 98.14 | 3.67 | 160 |
| Talebian[46] | 2004-2006 | Tehran | 4-6 | Historical cohort | 100 | 16.23 | 102 |
| Rahmani[47] | 2012 | Sanandaj | 27.06 | Before-after study | 93.58 | 10.34 | 60 |
| Vaezi[9] | 2012 | Tehran | 8-10 | - | 97.79 | 11.69 | 25 |
| Hashemi[48] | 2009-2011 | Fars | 6-9 | Experimental | 96.5 | 12.42 | 60 |
| Ashtari[49] | 2013 | Isfahan | 19-60 | Cross-sectional | 82.56 | 8.91 | 100 |
| Saremi[50] | 2013-2015 | Mashhad | 20-40 | Causal-comparative | 109.92 | 4.7 | 70 |
| Ghaffari[51] | 2011 | Mazandaran | 6-14 | Comparative | 108.8 | 11.92 | 180 |
| Ahmadi[52] | 2014 | Yazd | 6-9 | - | 105.87 | - | 75 |
| Khadem[53] | 2010 | Mashhad | 6-7 | Cross-sectional | 100.4 | 4.33 | 372 |
| Faramarzi[54] | 2011-2012 | Babol | 5-6.5 | Cross-sectional | 109.6 | 13.41 | 60 |
| Tonekaboni[55] | 2003-2004 | Tehran | 6-12 | - | 94.42 | 18.8 | 45 |
| Azizi[56] | 2002 | Tehran | 3-11 | - | 114.73 | 12.7 | 53 |
| Azizi[57] | 1377 | Tehran | 4-6 | - | 103 | 13.29 | 31 |
| Najmi[58] | 2013 | Isfahan | 4.5 | Comparative | 97.1 | 9.66 | 120 |
| Mahram[59] | 2009 | Zanjan | 6 | Cohort | 96.5 | 9.66 | 130 |
| Ordooei[60] | 2007 | Yazd | 5 | Case-control | 108.9 | 2.78 | 80 |