Summary of findings 1. Summary of findings table ‐ Vitamin D compared to placebo for the management of asthma.
| Vitamin D compared to placebo for the management of asthma | ||||||
| Patient or population: children and adults with predominantly mild to moderate asthma Setting: primary and secondary care Intervention: vitamin D Comparison: placebo | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with placebo | Risk with vitamin D | |||||
| Proportion of participants with one or more exacerbations treated with systemic corticosteroids follow‐up: range 3 months to 40 months | 219 per 1000 | 226 per 1000 (185 to 273) | OR 1.04 (0.81 to 1.34) | 1778 (14 RCTs) | ⊕⊕⊕⊕ Higha | |
| Proportion of participants with one or more exacerbations requiring emergency department visit or hospitalisation, or both | 79 per 1000 | 46 per 1000 (22 to 94) | OR 0.56 (0.26 to 1.21) | 1070 (9 RCTs) | ⊕⊕⊕⊝ Moderateb | |
| End‐study asthma control test score assessed with: childhood Asthma Control Test, or linearly transformed Asthma Control Test Scale from: 0 to 27 | The mean end‐study asthma control test score was 22.98 points | MD 0.23 points higher (0.26 lower to 0.73 higher) | ‐ | 1271 (7 RCTs) | ⊕⊕⊕⊝ Moderatec | |
| End‐study forced expiratory volume in 1 second, % predicted | The mean end‐study forced expiratory volume in 1 second, % predicted was 93.80 % | MD 0.2 % higher (1.24 lower to 1.63 higher) | ‐ | 1286 (11 RCTs) | ⊕⊕⊕⊕ High | |
| Proportion of participants with one or more serious adverse events due to any cause | 55 per 1000 | 49 per 1000 (32 to 76) | OR 0.89 (0.56 to 1.41) | 1556 (12 RCTs) | ⊕⊕⊕⊕ High | |
| Proportion of participants with fatal asthma exacerbation | 0 per 1000 | 0 per 1000 (0 to 0) | Not estimable | 1976 (16 RCTs) | ⊕⊕⊝⊝ Lowd | |
| Withdrawals from trial | 86 per 1000 | 90 per 1000 (68 to 119) | OR 1.05 (0.77 to 1.43) | 2225 (20 RCTs) | ⊕⊕⊕⊕ High | |
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; MD: mean difference; OR: odds ratio | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
| See interactive version of this table: https://gdt.gradepro.org/presentations/#/isof/isof_question_revman_web_436923543367697621. | ||||||
a Each of these GRADE assessments is discussed in full under Quality of the evidence. b Downgraded one level due to imprecision, as 95% CI ranged from 0.26 to 1.21 and evidence drew on fewer studies than the primary outcome c Downgraded one level due to heterogeneity, as I² = 29% d Downgraded two levels due to imprecision, as no events occurred in either arm of any trial considered