[Retracted] Effects of Vitamin D on Respiratory Function and Immune Status for Patients with Chronic Obstructive Pulmonary Disease (COPD): A Systematic Review and Meta-Analysis

Table 2

The summary of findings.

Experimental group vs. control group for COPD
Patient or population: Patients with COPD; Settings: Intervention: Vitamin D or vitamin D + routine treatment; Comparison: Placebo or routine treatment
Outcomes	Illustrative comparative risks(95% CI)			Relative effect (95% CI)	No. of participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Control group	Experimental group
FEV1		The mean FEV1 in the intervention groups was 5.66 higher (4.98 to 6.35 higher)			1592 (16 studies)	⊕ ⊕ ⊝⊝ low^1
FEV1/FVC		The mean FEV1/FVC in the intervention groups was 0.36 standard deviations higher (0.25 to 0.47 higher)			1336 (12 studies)	⊕ ⊕ ⊝⊝ low^1	SMD 0.36 (0.25 to 0.47)
25(OH)D		The mean 25(OH)D in the intervention groups was 7.32 higher (7.11 to 7.53 higher)			1259 (12 studies)	⊕⊝⊝⊝ very low^1
CD3^+		The mean CD3^+ in the intervention groups was 6.67 higher (5.34 to 8 higher)			609 (6 studies)	⊕⊝⊝⊝ very low^1
CD4^+		The mean CD4^+ in the intervention groups was 6 higher (5.01 to 7 higher)			715 (7 studies)	⊕ ⊕ ⊝⊝ low^1
CD8^+		The mean CD8^+ in the intervention groups was 1.19 lower (2.4 lower to 0.01 higher)			528 (5 studies)	⊕⊝⊝⊝ very low^1
CD4^+/CD8^+		The mean CD4^+/CD8^+ in the intervention groups was 0.41 higher (0.2 to 0.61 higher)			715 (7 studies)	⊕ ⊕ ⊝⊝ low^1
Acute exacerbation		Study population		RR 0.4 (0.28 to 0.59)	571 (7 studies)	⊕ ⊕ ⊕⊝ moderate^1
		288 per 1000	115 per 1000 (81 to 170)
		Moderate
		267 per 1000	107 per 1000 (75 to 158)
CAT scores		The mean CAT scores in the intervention groups were 3.77 lower (5.86 to 1.68 lower)			289 (4 studies)	⊕⊝⊝⊝ very low^1

The basis for the assumed risk (e.g,. the median control group risk across studies) is provided in footnotes. The corresponding risk (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; RR: risk ratio; GRADE: Working Group grades of evidence. High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate. ¹ No explanation was provided.