Table 4.
Sensitivity analysis for daily or weekly supplementation of vitamin D
| Group | Study number; Patient number | Dose–response meta-analysis, RR (95% CI) | Pairwise Meta-analysis, RR (95% CI) | ||
|---|---|---|---|---|---|
| 400 IU/d | 800 IU/d | 1200 IU/d | |||
| Sensitivity analysis | |||||
| Daily or weekly administration [28, 29, 31–35, 39–42, 44, 45, 49, 50, 52, 54, 56–62, 64, 65, 69, 70] | 28; 21,652 | 0.95 (0.90–1.01) | 0.93 (0.86–1.01) | 0.94 (0.87–1.01) | 0.95 (0.91–0.99) |
| Subgroups | |||||
| Age group (years) | |||||
| < 7 [32, 39, 42, 52, 54, 56, 60, 69] | 8; 4693 | 0.90 (0.82–0.98) | 0.88 (0.79–0.98) | 0.89 (0.81–0.98) | 0.94 (0.88–1.01) |
| 7–17 [31, 33, 35, 44, 45, 61, 64, 65] | 8; 11,463 | 0.68 (0.00–1.3e + 24) | 0.64 (0.00–1.5e + 27) | 0.73 (0.00–2.2e + 19) | 0.95 (0.82–1.09) |
| 18–65 [28, 29, 34, 40, 41, 49, 50, 57, 59, 70] | 10; 3079 | 0.94 (0.84–1.05) | 0.90 (0.76–1.06) | 0.88 (0.74–1.04) | 0.88 (0.76–1.02) |
| > 65[58, 62] | 2; 2417 | NA | NA | NA | 1.01 (0.88–1.16) |
| Gender proportion (%) | |||||
| Male > 60 [29, 33, 41, 44, 45] | 5; 1114 | 0.63 (0.39–1.01) | 0.72 (0.52–1.01) | 0.83 (0.66–1.05) | 0.85 (0.67–1.07) |
| Male ≤ 60 [28, 31, 32, 34, 35, 39, 40, 42, 49, 50, 52, 54, 56–62, 64, 65, 69, 70] | 23; 20,538 | 0.97 (0.92–1.03) | 0.96 (0.89–1.04) | 0.96 (0.90–1.03) | 0.96 (0.92–1.00) |
| Comorbidity | |||||
| General [28, 29, 31, 35, 41, 42, 44, 45, 49, 52, 54, 56–58, 60–62, 64, 65, 69, 70] | 21; 17,863 | 0.92 (0.00–3.2e + 26) | 0.89 (0.00–1.9e + 37) | 0.90 (0.00–1.4e + 33) | 0.92 (0.85–0.99) |
| Disease-specific [32–34, 39, 40, 50, 59] | 7; 3789 | 0.81 (0.64–1.04) | 0.82 (0.67–1.02) | 0.84 (0.68–1.03) | 0.90 (0.78–1.04) |
| Baseline 25-hydroxyvitamin D levels (nmol/L) | |||||
| < 50 [35, 50, 54, 57, 64, 70] | 6; 10,379 | 0.85 (0.65–1.12) | 0.86 (0.68–1.09) | 0.87 (0.67–1.11) | 0.90 (0.75–1.07) |
| > 50 [28, 29, 33, 34, 39, 40, 42, 45, 49, 52, 56, 58–62, 65] | 17; 7669 | 0.97 (0.91–1.03) | 0.95 (0.87–1.04) | 0.95 (0.88–1.04) | 0.94 (0.89–1.00) |
| Trial duration (months) | |||||
| < 4 [28, 35, 41, 44, 45, 57, 58, 69, 70] | 9; 2392 | 0.88 (0.62–1.26) | 0.84 (0.52–1.35) | 0.84 (0.55–1.29) | 0.81 (0.64–1.02) |
| 4–12 [29, 31–33, 39, 42, 49, 50, 52, 59–61, 65] | 13; 6064 | 0.89 (0.82–0.98) | 0.87 (0.77–0.98) | 0.89 (0.80–0.99) | 0.93 (0.85–1.01) |
| > 12 [34, 40, 54, 56, 62, 64] | 6; 13,196 | 1.00 (0.92–1.09) | 1.00 (0.92–1.10) | 1.00 (0.94–1.07) | 1.00 (0.98–1.02) |
| Climatic zone | |||||
| Tropical or Subtropical [61, 65, 69, 70] | 4; 2154 | NA | NA | NA | 0.73 (0.42–1.26) |
| Temperate [28, 29, 31–35, 39–42, 44, 45, 49, 50, 52, 54, 56–60, 62, 64] | 24; 19,498 | 0.94 (0.89–0.99) | 0.92 (0.85–0.99) | 0.93 (0.87–0.99) | 0.96 (0.92–1.00) |
| Summer | |||||
| Summer-inclusive [32, 34, 40, 42, 49, 52, 54, 56–59, 62, 64, 65, 69, 70] | 16; 17,788 | 1.01 (0.96–1.06) | 1.01 (0.94–1.08) | 1.00 (0.94–1.07) | 0.98 (0.95–1.02) |
| Summer-sparing [28, 29, 31, 33, 35, 39, 41, 44, 45, 50, 60, 61] | 12; 3864 | 0.80 (0.71–0.91) | 0.74 (0.65–0.89) | 0.78 (0.66–0.92) | 0.85 (0.73–1.00) |
| Winter | |||||
| Winter-dominant [28, 29, 31, 35, 39, 44, 45, 60] | 8; 1658 | 0.69 (0.58–0.82) | 0.70 (0.59–0.82) | 0.80 (0.69–0.93) | 0.79 (0.68–0.92) |
| Winter-non-dominant [32–34, 40–42, 49, 50, 52, 54, 56–59, 61, 62, 64, 65, 69, 70] | 20; 19,994 | 0.99 (0.95–1.04) | 0.99 (0.93–1.05) | 0.99 (0.93–1.05) | 0.98 (0.94–1.02) |
| Sensitivity analysis | |||||
| Type of ARIs | |||||
| Mixed upper and lower respiratory tract infections [29, 32–35, 42, 49, 54, 56, 60, 62, 64, 65] | 13; 15,552 | 0.91 (0.82–1.02) | 0.90 (0.79–1.02) | 0.93 (0.84–1.02) | 0.95 (0.91–1.00) |
| Upper respiratory tract infections [28, 39–41, 45, 50, 52, 54, 57–59, 61] | 12; 5154 | 0.93 (0.86–1.00) | 0.90 (0.80–1.00) | 0.90 (0.79–1.01) | 0.97 (0.90–1.04) |
| Lower respiratory tract infections [54] | 1; 300 | NA | NA | NA | 0.94 (0.79–1.12) |
| Influenza [31, 44, 52, 58, 59, 61, 69] | 7; 3425 | 0.92 (0.74–1.15) | 0.89 (0.65–1.23) | 0.91 (0.67–1.24) | 0.96 (0.83–1.11) |
ARI Acute respiratory infection, NA Not available