Table 3 Studies of the rs1946518 and rs187238 polymorphisms in IL-18 gene and risk of RA and SLE under additive model grouped by study characteristics

rs1946518

7

77.80%

0.752(0.562-1.006)

0.055

6

88.10%

0.684(0.455-1.028)

0.068

Population

 Chinese

4

52.90%

0.688(0.532-0.889)

0.004

5

87.00%

0.606(0.396-0.930)

0.022

 Other

3

40.10%

1.074(0.958-1.205)

0.702

1

NA

1.250(0.883-1.771)

0.208

Genotyping method

 PCR-SSP

5

36.50%

0.636(0.519-0.781)

<0.001

2

96.70%

0.596(0.139-2.560)

0.487

 PCR–RFLP

1

NA

0.817(0.604-1.105)

0.189

3

74.60%

0.670(0.454-0.989)

0.044

 other

1

NA

1.088(0.969-1.222)

0.155

1

NA

0.945(0.686-1.303)

0.731

Sample size

 ≥300

3

50.60%

0.959(0.781-1.178)

0.693

3

76.80%

0.773(0.519-1.152)

0.207

 <300

4

0.00%

0.559(0.438-0.715)

<0.001

3

93.50%

0.605(0.267-1.369)

0.228

HWE status

 Meeting HWE

6

81.30%

0.727(0.513-1.031)

0.073

6

88.10%

0.684(0.455-1.028)

0.068

 Deviating HWE

1

NA

0.857(0.590-1.244)

0.416

0

NA

NA

NA

rs187238

5

48.90%

1.296(0.959-1.751)

0.246

5

33.70%

1.166(0.948-1.435)

0.145

Population

 Chinese

3

70.30%

1.262(0.703-2.264)

0.436

4

45.60%

1.209(0.961-1.520)

0.105

 Other

2

0.00%

1.628(0.631-4.199)

0.314

1

NA

0.996(0.614-1.616)

0.986

Genotyping method

 PCR-SSP

5

48.90%

1.296(0.959-1.751)

0.246

3

0.00%

1.300(0.991-1.705)

0.416

 Other

0

NA

NA

NA

2

65.10%

0.987(0.570-1.710)

0.963

Sample size

 ≥150

3

70.30%

1.262(0.703-2.264)

0.436

2

0.00%

1.351(0.990-1.845)

0.058

 <150

2

0.00%

1.628(0.631-4.199)

0.314

3

54.70%

1.040(0.686-1.577)

0.854

HWE status

 Meeting HWE

5

48.90%

1.296(0.959-1.751)

0.246

4

34.20%

1.095(0.870-1.377)

0.439

 Deviating HWE

0

NA

NA

NA

1

NA

1.537(0.942-2.508)

0.085