@article{PradaMaagSiegmundetal.2022,
  author    = {Prada, Juan Pablo and Maag, Luca Estelle and Siegmund, Laura and Bencurova, Elena and Liang, Chunguang and Koutsilieri, Eleni and Dandekar, Thomas and Scheller, Carsten},
  title     = {Estimation of R0 for the spread of SARS-CoV-2 in Germany from excess mortality},
  series = {Scientific Reports},
  volume    = {12},
  journal   = {Scientific Reports},
  number    = {1},
  doi       = {10.1038/s41598-022-22101-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301415},
  year      = {2022},
  abstract  = {For SARS-CoV-2, R0 calculations in the range of 2-3 dominate the literature, but much higher estimates have also been published. Because capacity for RT-PCR testing increased greatly in the early phase of the Covid-19 pandemic, R0 determinations based on these incidence values are subject to strong bias. We propose to use Covid-19-induced excess mortality to determine R0 regardless of RT-PCR testing capacity. We used data from the Robert Koch Institute (RKI) on the incidence of Covid cases, Covid-related deaths, number of RT-PCR tests performed, and excess mortality calculated from data from the Federal Statistical Office in Germany. We determined R0 using exponential growth estimates with a serial interval of 4.7 days. We used only datasets that were not yet under the influence of policy measures (e.g., lockdowns or school closures). The uncorrected R0 value for the spread of SARS-CoV-2 based on RT-PCR incidence data was 2.56 (95\% CI 2.52-2.60) for Covid-19 cases and 2.03 (95\% CI 1.96-2.10) for Covid-19-related deaths. However, because the number of RT-PCR tests increased by a growth factor of 1.381 during the same period, these R0 values must be corrected accordingly (R0corrected = R0uncorrected/1.381), yielding 1.86 for Covid-19 cases and 1.47 for Covid-19 deaths. The R0 value based on excess deaths was calculated to be 1.34 (95\% CI 1.32-1.37). A sine-function-based adjustment for seasonal effects of 40\% corresponds to a maximum value of R0January = 1.68 and a minimum value of R0July = 1.01. Our calculations show an R0 that is much lower than previously thought. This relatively low range of R0 fits very well with the observed seasonal pattern of infection across Europe in 2020 and 2021, including the emergence of more contagious escape variants such as delta or omicron. In general, our study shows that excess mortality can be used as a reliable surrogate to determine the R0 in pandemic situations.},
  language  = {en}
}
@article{MengerLeeNotzetal.2022,
  author    = {Menger, Johannes and Lee, Zheng-Yii and Notz, Quirin and Wallqvist, Julia and Hasan, M. Shahnaz and Elke, Gunnar and Dworschak, Martin and Meybohm, Patrick and Heyland, Daren K. and Stoppe, Christian},
  title     = {Administration of vitamin D and its metabolites in critically ill adult patients: an updated systematic review with meta-analysis of randomized controlled trials},
  series = {Critical Care},
  volume    = {26},
  journal   = {Critical Care},
  number    = {1},
  doi       = {10.1186/s13054-022-04139-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299700},
  year      = {2022},
  abstract  = {Background The clinical significance of vitamin D administration in critically ill patients remains inconclusive. The purpose of this systematic review with meta-analysis was to investigate the effect of vitamin D and its metabolites on major clinical outcomes in critically ill patients, including a subgroup analysis based on vitamin D status and route of vitamin D administration. Methods Major databases were searched through February 9, 2022. Randomized controlled trials of adult critically ill patients with an intervention group receiving vitamin D or its metabolites were included. Random-effect meta-analyses were performed to estimate the pooled risk ratio (dichotomized outcomes) or mean difference (continuous outcomes). Risk of bias assessment included the Cochrane tool for assessing risk of bias in randomized trials. Results Sixteen randomized clinical trials with 2449 patients were included. Vitamin D administration was associated with lower overall mortality (16 studies: risk ratio 0.78, 95\% confidence interval 0.62-0.97, p = 0.03; I2 = 30\%), reduced intensive care unit length of stay (12 studies: mean difference - 3.13 days, 95\% CI - 5.36 to - 0.89, n = 1250, p = 0.006; I2 = 70\%), and shorter duration of mechanical ventilation (9 studies: mean difference - 5.07 days, 95\% CI - 7.42 to - 2.73, n = 572, p < 0.0001; I2 = 54\%). Parenteral administration was associated with a greater effect on overall mortality than enteral administration (test of subgroup differences, p = 0.04), whereas studies of parenteral subgroups had lower quality. There were no subgroup differences based on baseline vitamin D levels. Conclusions Vitamin D supplementation in critically ill patients may reduce mortality. Parenteral administration might be associated with a greater impact on mortality. Heterogeneity and assessed certainty among the studies limits the generalizability of the results.},
  language  = {en}
}