Table 1. Characteristics of published studies included in this meta-analysis.
| First author & year | Ethnicity | Studydesign | CKDtype | Kidneyfunctionof case | Definition of case |
| Shaikh, 2012 [27] | Caucasian | CC | DN | non-ESRD | UAE >300 mg/day11 |
| Rahimi, 2012 [28] | Caucasian | CS | DN | non-ESRD | ACR >30 mg/g |
| El-Baz, 2012 [29] | Caucasian | CS | DN | non-ESRD | ACR >30 mg/g |
| Zsom(1), 2011 [30] | Caucasian | CC | non-DN | non-ESRD | biopsy, ultrasound diagnosed & eGFR <60 ml/min/1.73 m2 |
| Zsom(2), 2011 [30] | Caucasian | CC | DN | non-ESRD | proteinuria & eGFR <60 ml/min/1.73 m2 |
| Al-Harbi, 2011 [31] | Caucasian | CC | DN | non-ESRD | no description |
| Jung, 2011 [32] | Asian | CC | GN | non-ESRD | biopsy diagnosed |
| Ali, 2011 [33] | Asian | CC | Comb | ESRD | doctor diagnosed |
| Huang, 2010 [34] | Asian | CC | GN | ESRD | biopsy diagnosed |
| Jayapalan, 2010 [35] | Asian | CS | DN | non-ESRD | ACR >30 mg/g or RRT |
| Mansoor, 2010 [14] | Caucasian | CS | DN | non-ESRD | albuminuria or RRT |
| Naresh, 2009 [36] | Asian | CC | DN | non-ESRD | no description |
| Ezzidi, 2009 [37] | Caucasian | CS | DN | non-ESRD | ACR >30 mg/g or eGFR <90 ml/min/1.73 m2 |
| Nikzamir, 2009 [38] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Anbazhagan, 2009 [39] | Asian | CC | Comb | ESRD | RRT |
| Ahluwalia, 2009 [40] | Asian | CC | DN | non-ESRD | UAE >200 µg/min, ACR >300 mg/g orRRT |
| Palomo-Piñón, 2009 [16] | Caucasian | CS | DN | non-ESRD | ACR >30 mg/g |
| Möllsten, 2008 [41] | Caucasian | CS | DN | non-ESRD | ACR >20 mg/g |
| Eroglu, 2008 [42] | Caucasian | CC | DN | non-ESRD | 30 mg/day<UAE <300 mg/day |
| Arfa, 2008 [43] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Tripathi, 2008 [44] | Asian | CC | non-DN | ESRD | CCr <15 mL/min/1.73 m2 & ultrasound diagnosedor CT |
| Movva, 2007 [45] | Asian | CC | DN | ESRD | SCr >1.5 mg/dL and UAE >30 mg/day |
| Uddin, 2007 [46] | Asian | CC | DN | ESRD | porteinuria |
| Buraczynska, 2006 [47] | Caucasian | CC | Comb | ESRD | RRT |
| So, 2006 [48] | Asian | CS | DN | non-ESRD | ACR >30 mg/g |
| Shestakova, 2006 [49] | Caucasian | CC | DN | non-ESRD | ACR >300 mg/g |
| Ng, 2006 [50] | Caucasian | CS | DN | non-ESRD | urinalyses positive, ACR >250 mg/g (men) or >355 mg/g (women) |
| Prasad, 2006 [51] | Asian | CC | DN | non-ESRD | SCr >3 mg/dL?ACR >200 mg/g |
| Degirmenci, 2005 [52] | Caucasian | CS | DN | ESRD | UAE >30 mg/day |
| van der Sman-de Beer, 2005 [53] | Caucasian | CC | Comb | non-ESRD | RRT |
| Park, 2005 [18] | Asian | CC | DN | ESRD | RRT |
| Canani, 2005 [54] | Caucasian | CS | DN | non-ESRD | UAE >20 µg/min |
| Fabris, 2005 [55] | Caucasian | CC | HN | non-ESRD | SCr >1.5 mg/dL |
| Lau, 2004 [56] | Asian | CC | GN | ESRD | biopsy diagnosed |
| Suzuki, 2004 [57] | Asian | CC | GN | non-ESRD | biopsy diagnosed |
| Stratta, 2004 [58] | Caucasian | CC | GN | non-ESRD | biopsy diagnosed |
| Lochynska, 2003 [59] | Caucasian | CC | GN | non-ESRD | biopsy diagnosed |
| Papp, 2003 [60] | Caucasian | CC | GN | ESRD | RRT |
| Aucella, 2003 [61] | Caucasian | CC | Comb | non-ESRD | RRT |
| Okuno, 2003 [62] | Asian | CS | DN | non-ESRD | UAE >10 µg/min |
| Ortiz, 2003 [63] | Caucasian | CC | non-DN | non-ESRD | CCr <50 mL/min/1.73 m2 |
| Hadjadj, 2003 [15] | Caucasian | CC | DN | non-ESRD | urinary albumin concentration >20 mg/L |
| Wang, 2003 [64] | Asian | CC | Comb | ESRD | RRT |
| Dixit, 2002 [65] | Caucasian | CC | GN | ESRD | biopsy diagnosed |
| Lee(1), 2002 [26] | Asian | CS | non-DN | non-ESRD | UAE >20 µg/min or ACR >20 mg/g |
| Lee(2), 2002 [26] | Asian | CS | DN | non-ESRD | UAE >20 µg/min or ACR >20 mg/g |
| Losito, 2002 [66] | Caucasian | CC | Comb | ESRD | RRT |
| Yoon, 2002 [67] | Asian | CC | GN | non-ESRD | biopsy diagnosed |
| Fradin, 2002 [68] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Drouet, 2002 [69] | Caucasian | CC | GN | non-ESRD | biopsy diagnosed |
| Nicod, 2002 [70] | Caucasian | CC | Comb | non-ESRD | RRT |
| Araz, 2001 [71] | Caucasian | CS | DN | non-ESRD | ACR >30 mg/g |
| Azar, 2001 [72] | Caucasian | CC | DN | non-ESRD | UAE >30 mg/day |
| Lovati, 2001 [73] | Caucasian | CC | Comb | ESRD | RRT |
| Wang, 2001 [74] | Caucasian | CS | Comb | non-ESRD | CCr <60 mL/min/1.73 m2 |
| Taniwaki, 2001 [75] | Asian | CS | DN | non-ESRD | UAE >30 mg/day |
| Viswanathan, 2001 [76] | Asian | CC | DN | non-ESRD | proteinuria >500 mg/dL |
| Hadjadj, 2001 [77] | Caucasian | CS | DN | non-ESRD | urinary albumin concentration >20 mg/L |
| Wu, 2000 [78] | Asian | CC | DN | non-ESRD | no description |
| Hsieh, 2000 [79] | Asian | CC | DN | non-ESRD | proteinuria >500 mg/dL |
| van Ittersum, 2000 [80] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Tomino, 1999 [19] | Asian | CS | DN | non-ESRD | UAE >20 µg/min or ACR >30 mg/g |
| Solini, 1999 [81] | Caucasian | CS | DN | non-ESRD | Albuminuria |
| De Cosmo, 1999 [82] | Caucasian | CC | DN | non-ESRD | UAE >30 mg/day |
| Miura, 1999 [83] | Asian | CS | DN | non-ESRD | UAE >10 µg/min |
| Kuramoto, 1999 [84] | Asian | CS | DN | non-ESRD | UAE >15 µg/min |
| Huang, 1998 [85] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Walder, 1998 [86] | Caucasian | CC | DN | non-ESRD | UAE >30 mg/day |
| Freire, 1998 [87] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Grzeszczak, 1998 [88] | Caucasian | CS | DN | non-ESRD | ACR >1.9 mg/mol (men) or >2.8 mg/mol (women) |
| Young, 1998 [89] | Asian | CS | DN | non-ESRD | UAE >30 mg/day |
| Penno, 1998 [90] | Caucasian | CS | DN | non-ESRD | UAE >20 µg/min |
| Fernández-Llama, 1998 [91] | Caucasian | CS | HN | non-ESRD | UAE >20 µg/min |
| Frost, 1998 [92] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Pei, 1997 [93] | Caucasian | CS | GN | non-ESRD | biopsy diagnosed |
| Marre, 1997 [94] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Barnas, 1997 [95] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Ringel, 1997 [96] | Caucasian | CC | DN | non-ESRD | UAE >30 mg/day |
| Schmidt, 1997 [97] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Kawada, 1997 [98] | Asian | CC | Comb | ESRD | RRT |
| Kario, 1997 [99] | Asian | CS | HN | non-ESRD | UAE >15 µg/min |
| Nakajima, 1996 [17] | Asian | CS | DN | non-ESRD | ACR >30 mg/g |
| Chowdhury, 1996 [100] | Caucasian | CS | DN | non-ESRD | Albuminuria |
| McLaughlin, 1996 [101] | Caucasian | CC | Comb | non-ESRD | RRT or doctor diagnosed |
| Oh, 1996 [102] | Asian | CS | DN | non-ESRD | UAE >20 µg/min |
| Schmidt, 1996 [103] | Caucasian | CC | Comb | ESRD | RRT |
| Doi, 1996 [104] | Asian | CS | DN | non-ESRD | ACR >30 mg/g |
| Ohno, 1996 [105] | Asian | CS | DN | non-ESRD | ACR >10 mg/g |
| Mizuiri, 1995 [106] | Asian | CC | DN | non-ESRD | UAE >20 µg/min or RRT |
| Yorioka, 1995 [107] | Asian | CC | GN | non-ESRD | biopsy diagnosed |
| Fujisawa, 1995 [108] | Asian | CS | DN | non-ESRD | Albuminuria or RRT |
| Panagiotopoulos, 1995 [109] | Caucasian | CS | DN | non-ESRD | UAE >20 µg/min |
| Tarnow, 1995 [110] | Caucasian | CC | DN | non-ESRD | UAE >300 mg/day or biopsy diagnosed |
| Schmidt, 1995 [111] | Caucasian | CC | GN | non-ESRD | biopsy diagnosed |
| Yoshida, 1995 [112] | Asian | CC | GN | non-ESRD | biopsy diagnosed |
| Dudley, 1995 [113] | Caucasian | CC | DN | non-ESRD | patients with urine in top tertile of the median UAE |
| Harden, 1995 [114] | Caucasian | CC | GN | non-ESRD | biopsy diagnosed |
| Doria, 1994 [115] | Caucasian | CC | DN | non-ESRD | UAE >30 µg/min |
| Marre, 1994 [116] | Caucasian | CS | DN | non-ESRD | UAE >30 mg/day |
| Powrie, 1994 [117] | Caucasian | CS | DN | non-ESRD | ACR >3 mg/mmol |
CC: case control study; CS: cross-sectional survey; DN: diabetic nephropathy; non-DN: non diabetic nephropathy; GN: glomerulonephritis; HN: hypertensive nephropathy; Comb: combined; ESRD: only ESRD patients; non-ESRD: not only ESRD patients; UAE: urinary albumin excretion rate; ACR: Albumin creatinine ratio; eGFR: estimated glomerular filtration rate; CCr: creatinine clearance; RRT: renal replacement therapy; CT: computed tomography; SCr: serum creatinine.