Table 2 Results of subgroup analysis
Subgroup analyses | Crohn disease | Ulcerative colitis | ||||||
|---|---|---|---|---|---|---|---|---|
No. of effect sizes | Mean (95% CI) | P for mean | I2 (%) | No. of effect sizes | Mean (95% CI) | P for mean | I2 (%) | |
25(OH)D among disease patients and healthy controls | ||||||||
Maturity | ||||||||
Adults (> 18 years old) | 24 | − 3.22 (− 4.75 to − 1.70) | < 0.01 | 90 | 11 | − 2.38 (− 4.20 to − 0.56) | < 0.01 | 85 |
Children (< 18 years old) | 8 | − 3.61 (− 4.89 to − 2.32) | < 0.01 | 90 | 4 | − 4.45 (− 9.42 to 0.53) | < 0.01 | 78 |
Vitamin D assessment tool | ||||||||
CLIA | 5 | − 1.32(− 8.89 to 6.26) | < 0.01 | 95 | 2 | − 3.10 (− 7.50 to 1.30) | 0.2 | 38 |
CLIA + LC–MS | 1 | − 0.20 (− 2.90 to 2.50) | NR | NR | 0 | NR | NR | NR |
CPBA | 5 | − 4.28 (− 6.40 to − 2.16) | 0.06 | 55 | 1 | − 1.10 (− 2.31 to 0.11) | NR | NR |
ELISA | 6 | − 8.29 (− 13.83 to − 2.76) | < 0.01 | 85 | 3 | − 8.22 (− 16.62 to 0.19) | < 0.01 | 86 |
HPLC | 3 | − 3.23 (− 9.40 to 2.95) | 0.09 | 58 | 1 | − 7.00 (− 11.58 to − 2.42) | NR | NR |
LC–MS | 3 | − 0.35 (− 0.99 to 0.29) | 0.25 | 27 | 2 | − 0.15 (− 0.57 to 0.27) | 0.77 | 0 |
RIA | 8 | − 4.46 (− 9.05 to 0.13) | < 0.01 | 90 | 4 | − 4.52 (− 12.89 to 3.85) | < 0.01 | 89 |
NR | 1 | 3.11 (− 3.37 to 9.59) | NR | NR | ||||
Vitamin D supplementation | ||||||||
No | 24 | − 3.46 (− 4.90 to − 2.03) | < 0.01 | 91 | 12 | − 3.29 (− 4.99 to − 1.60) | < 0.01 | 87 |
Yes | 7 | − 1.49 (− 4.40 to 1.42) | < 0.01 | 66 | 3 | 0.72 (− 1.98 to 3.41) | 0.95 | 0 |
NR | 1 | − 12.14 (− 19.54 to − 4.74) | NR | NR | 0 | NR | NR | NR |
Study design | ||||||||
Case–control study | 19 | − 4.95 (− 7.85 to − 3.11) | < 0.01 | 89 | 7 | − 2.24 (− 4.59 to 0.11) | < 0.01 | 79 |
Cohort study | 9 | − 2.11 (− 3.69 to -0.53) | < 0.01 | 82 | 4 | − 2.58 (− 5.29 to 0.13) | < 0.01 | 89 |
Cross-sectional study | 4 | − 0.44 (− 6.76 to 5.87) | < 0.01 | 93 | 1 | − 18.07 (− 26.50 to -9.64) | NR | NR |
25(OH)D among disease patients and non-healthy controls | ||||||||
Maturity | ||||||||
Adults (> 18 years old) | 28 | − 0.84 (− 2.12 to 0.44) | < 0.01 | 85 | 26 | 0.65 (− 0.65 to 1.95) | < 0.01 | 86 |
Children (< 18 years old) | 9 | 0.53 (− 2.16 to 3.22) | < 0.01 | 78 | 8 | 0.92 (− 2.05 to 3.90) | < 0.01 | 79 |
NR | 1 | − 1.88 (− 5.52 to 1.76) | NR | NR | 1 | 1.88 (− 1.76 to 5.52) | NR | NR |
Vitamin D assessment tool | ||||||||
CLIA | 7 | 1.66 (− 1.36 to 4.68) | < 0.01 | 73 | 6 | − 0.81 (− 3.96 to 2.43) | < 0.01 | 73 |
CPBA | 7 | − 0.80 (− 2.79 to 1.20) | < 0.01 | 76 | 6 | 1.94(− 0.03 to 3.91) | < 0.01 | 78 |
ECLIA | 2 | 1.34 (0.17 to 2.52) | 0.62 | 0 | 2 | − 1.34 (− 2.52 to − 0.17) | 0.23 | 31 |
ELISA | 4 | 1.60 (− 5.26 to 2.07) | < 0.01 | 84 | 1 | 0.18 (− 3.65 to 4.01) | NR | NR |
HPLC | 2 | − 3.27 (− 6.35 to 0.19) | 0.53 | 0 | 1 | 3.69 (0.34 to 7.04) | NR | NR |
LC–MS | 2 | 0.96 (− 0.84 to 2.76) | 0.02 | 80 | 2 | − 0.96 (− 2.76 to 0.84) | 0.02 | 80 |
RIA | 10 | − 1.65 (− 5.16 to 1.86) | < 0.01 | 85 | 9 | 1.18 (− 2.61 to 4.98) | < 0.01 | 87 |
NR | 4 | − 2.35 (− 4.91 to − 0.20) | 0.67 | 0 | 2 | 2.35 (− 0.20 to 4.91) | 0.45 | 0 |
Vitamin D supplementation | ||||||||
No | 34 | − 0.48 (− 1.70 to 0.74) | < 0.01 | 84 | 31 | − 0.71 (− 0.63 to -2.05) | < 0.01 | 85 |
Yes | 4 | − 2.36 (− 3.25 to − 1.46) | 0.45 | 0 | 3 | 2.36 (1.46 to 3.25) | 0.45 | 19 |
Study design | ||||||||
Case–control study | 12 | − 0.07 (− 1.77 to 1.64) | < 0.01 | 58 | 9 | 0.91 (− 1.09 to 2.91) | 0.37 | 68 |
Cohort study | 10 | 0.46 (− 1.28 to 2.20) | < 0.01 | 74 | 16 | 0.09 (− 1.52 to 1.69) | 0.92 | 78 |
Cross-sectional study | 10 | − 0.56 (− 4.21 to 3.10) | < 0.01 | 91 | 9 | 1.47 (− 1.56 to 4.50) | 0.34 | 91 |
1,25(OH)2D3 among disease patients and healthy controls | ||||||||
Maturity | ||||||||
Adults (> 18 years old) | 5 | 0.31 (− 12.88 to 13.50) | < 0.01 | 96 | 3 | − 2.94 (− 7.25 to 1.38) | 0.11 | 55 |
Children (< 18 years old) | 3 | 8.64 (− 14.08 to 31.35) | < 0.01 | 99 | 2 | 16.54 (− 2.85 to 35.94) | 0.01 | 84 |
Vitamin D assessment tool | ||||||||
CPBA | 1 | 15.70 (15.20 to 16.20) | NR | NR | 1 | − 0.80 (− 1.86 to 0.26) | NR | NR |
HPLC | 1 | − 8.62 (− 21.62 to 4.38) | NR | NR | NR | NR | NR | NR |
RIA | 5 | 3.07 (− 13.33 to 19.47) | < 0.01 | 97 | 3 | 4.31 (− 20.38 to 28.99) | < 0.01 | 97 |
NR | 1 | 3.20 (− 1.16 to 7.56) | NR | NR | 1 | 5.30 (− 9.49 to 20.09) | NR | NR |
Vitamin D supplementation | ||||||||
No | 8 | 3.47 (− 7.72 to 14.66) | < 0.01 | 98 | 5 | 3.76 (− 8.36 to 15.87) | < 0.01 | 96 |
Study design | ||||||||
Case–control study | 6 | 3.95 (− 9.09 to 16.98) | < 0.01 | 95 | 4 | 4.60 (− 15.56 to 24.77) | < 0.01 | 96 |
Cohort study | 2 | 2.14 (− 24.51 to 28.80) | < 0.01 | 100 | 1 | − 0.80 (− 1.86 to 0.26) | NR | NR |
1,25(OH)2D3 among disease patients and non-healthy controls | ||||||||
Maturity | ||||||||
Adults (> 18 years old) | 6 | 6.77 (− 2.30 to 15.84) | < 0.01 | 98 | 4 | − 10.48 (− 21.86 to 0.89) | < 0.01 | 96 |
Children (< 18 years old) | 3 | 1.40 (− 9.11 to 11.90) | 0.06 | 64 | 3 | − 1.40 (− 11.90 to 9.11) | 0.06 | 64 |
Vitamin D assessment tool | ||||||||
CPBA | 2 | 6.07 (− 15.64 to 27.79) | < 0.01 | 94 | 2 | − 6.07 (− 27.79 to 15.64) | < 0.01 | 94 |
HPLC + RIA | 1 | − 0.08 (− 4.59 to 4.43) | NR | NR | 0 | NR | NR | NR |
RIA | 4 | 0.87 (− 1.14 to 2.87) | 0.11 | 55 | 3 | − 3.51 (− 10.10 to 3.09) | 0.11 | 55 |
NR | 2 | 10.93 (− 13.44 to 35.31) | < 0.01 | 86 | 2 | − 10.93 (− 35.31 to 13.44) | < 0.01 | 86 |
Vitamin D supplementation | ||||||||
No | 9 | 5.05 (− 2.42 to 12.52) | < 0.01 | 97 | 7 | − 6.71 (− 15.30 to 1.88) | < 0.01 | 94 |
Study design | ||||||||
Case–control study | 6 | 0.60 (− 1.36 to 2.56) | 0.26 | 23 | 5 | − 1.00 (− 4.08 to 2.08) | 0.17 | 37 |
Cohort study | 2 | 16.57 (15.47 to 17.66) | 0.25 | 24 | 2 | − 16.57 (− 17.66 to − 15.47) | 0.25 | 24 |
Cross-sectional study | 1 | − 0.08 (− 4.59 to 4.43) | NR | NR | 0 | NR | NR | NR |