Outcome | Author, Year | Population Health Status | Outcome ascertainment | Reported summary risk estimate: Odds Ratio (OR), Risk Ratio(RR) (95% Confidence Interval); % Population infected (infected/population size) | ||||
---|---|---|---|---|---|---|---|---|
Deficient | Inadequate | Sufficient | Optimal | Per ↑ 10 nmol/L | ||||
Incidence of ARI/pneumonia | Laaksi, 2007 [19] | Healthy | Clinically diagnosed episodes of sinusitis, tonsillitis, otitis, bronchitis, pneumonia, pharyngitis, and laryngitis | 1.03 (0.90, 1.18)a,c; 88.9% (24/27) | – | 1.00 (reference); 86.1% (628/729) | – | – |
He, 2013 [17] | Healthy | Symptom diary; URTI was deemed present when (i) total symptom score was ≥15 on any two consecutive days and (ii) when a subject positively indicated suffering from a common cold on ≥3 days | NR; 66.7% (12/18) | NR; 39.7% (27/68) | NR; 43.8% (56/128) | NR; 27.3% (3/11) | – | |
Jovanonich, 2014 [18] | Mixedb | Laboratory confirmed CAP with chest radiograph | 2.57 (1.08, 6.08)d; NR | – | 0.96 (0.35, 2.61)d; NR | 1.03 (0.51, .09)d; NR | – | |
Rafiq, 2018 [20] | Mixedb | Self-reported episodes of cold in the month prior to questionnaire | – | – | – | – | 1.00 (0.96, 1.05)e; N/A | |
Sabetta, 2010 [24] | Healthy | Self-reported, followed by clinical diagnosis of acute viral RTI, which may or may not be laboratory confirmed | 1.00 (reference); 45.0% (81/180, 32 laboratory-confirmed cases) | – | – | 0.52 (0.25, 0.84)a; 16.7% (3/18; 1 laboratory-confirmed case) | – | |
Berry, 2011 [21] | Supposedly healthy | Self-reported episodes of respiratory infections (influenza, pneumonia, bronchitis, severe cold) in past 3 weeks prior to questionnaire | 1.00 (reference) | 0.94 (0.7, 1.27)f | 0.74 (0.54, 1.02)f | 75–99.9 nmol/L: 0.66 (0.46, 0.96)f; NR ≥100 nmol/L: 0.57 (0.34, 0.94)e; NR | 0.93, (0.89, 0.97)f; N/A | |
Nanri, 2017 [23] | Supposedly healthy | Self-reported to be clinically diagnosed with influenza, which may or may not be laboratory confirmed | 1.00 (reference)g; 32.8% (59/180) | 1.11 (0.74, 1.68)g; '28.6% (106/303) | 0.77 (0.37,1.59)g; 28.6% (14/49) | – | – | |
Lee, 2018 [22] | Healthy | Clinical diagnosis of ILI (retrospective retrieval from system) | 1.43 (0.77, 2.67)h; NR | 1.55 (0.84, 2.86)h; NR | 1.00 (reference); NR | – | – |