Vitamin D, SARS-CoV-2 and Causal Associations in Transversal Studies: The Time-Series Analysis to Reveal Potential Confounders. Comment on Gaudio et al. Vitamin D Levels Are Reduced at the Time of Hospital Admission in Sicilian SARS-CoV-2-Positive Patients. Int. J. Environ. Res. Public Health 2021, 18, 3491
- (1)
- It is objectively easier to draw biased conclusions due to an unrecognized biased selection of cases, rather than establishing a causal relationship by studying a single biological marker or even controlling all the possible (confounding) factors.
- (2)
- The cross-sectional design (through the comparison of means or medians) is always inadequate for studies that deal with a phenomenon that is subject to a complex temporal dynamics with multiple changes.
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References
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Parameters | Serum 25-OH Vitamin D | IgM+IgG Anti-COVID-19 Nuclecapsid Protein N (Ab-COV-N) | ||||||
---|---|---|---|---|---|---|---|---|
Coefficient (B) | std.Error | t-Statistic | p-Value | Coefficient (B) | std.Error | t-Statistic | p-Value | |
baseline level | 1.572 | 0.026 | 60.193 | <0.001 | 2.826 | 0.151 | 18.751 | <0.001 |
baseline slope | 9.25 × 10−5 | 0.000 | 0.186 | 0.852 | 0.004 | 0.003 | 1.224 | 0.222 |
step-change * | 0.149 | 0.074 | 2.011 | 0.045 | −0.862 | 0.427 | −2.02 | 0.044 |
trend-change * | 0.002 | 0.001 | 1.634 | 0.103 | −0.010 | 0.006 | −1.726 | 0.086 |
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Ialongo, C.; Farina, A.; Labriola, R.; Angeloni, A.; Anastasi, E. Vitamin D, SARS-CoV-2 and Causal Associations in Transversal Studies: The Time-Series Analysis to Reveal Potential Confounders. Comment on Gaudio et al. Vitamin D Levels Are Reduced at the Time of Hospital Admission in Sicilian SARS-CoV-2-Positive Patients. Int. J. Environ. Res. Public Health 2021, 18, 3491. Int. J. Environ. Res. Public Health 2021, 18, 6793. https://doi.org/10.3390/ijerph18136793
Ialongo C, Farina A, Labriola R, Angeloni A, Anastasi E. Vitamin D, SARS-CoV-2 and Causal Associations in Transversal Studies: The Time-Series Analysis to Reveal Potential Confounders. Comment on Gaudio et al. Vitamin D Levels Are Reduced at the Time of Hospital Admission in Sicilian SARS-CoV-2-Positive Patients. Int. J. Environ. Res. Public Health 2021, 18, 3491. International Journal of Environmental Research and Public Health. 2021; 18(13):6793. https://doi.org/10.3390/ijerph18136793
Chicago/Turabian StyleIalongo, Cristiano, Antonella Farina, Raffaella Labriola, Antonio Angeloni, and Emanuela Anastasi. 2021. "Vitamin D, SARS-CoV-2 and Causal Associations in Transversal Studies: The Time-Series Analysis to Reveal Potential Confounders. Comment on Gaudio et al. Vitamin D Levels Are Reduced at the Time of Hospital Admission in Sicilian SARS-CoV-2-Positive Patients. Int. J. Environ. Res. Public Health 2021, 18, 3491" International Journal of Environmental Research and Public Health 18, no. 13: 6793. https://doi.org/10.3390/ijerph18136793