ABSTRACT
This study evaluates the dynamic impact of various policies adopted by U.S. states, including social distancing, financial assistance, and vaccination policies. We propose a time-varying parameter multilevel dynamic factor model (TVP-MDFM) to improve the model's accuracy for evaluating the dynamic policy effect. The estimation is based on the Bayesian shrinkage method jointly with the Markov chain Monte Carlo (MCMC) algorithm that combines model selection and parameter estimation into the same iterative sampling process. The advantages and reliability of the TVP-MDFM are explored using simulation studies and robustness tests. The main empirical results highlight that the direct causal effect of the social distancing policy is more significant than the indirect effect mediated through human behavior. We also find income heterogeneity in financial assistance policies. Moreover, we provide evidence that banning vaccination certification by legislation is a stronger driver of the new case rate than executive orders during the Omicron dominance. © 2022 Elsevier B.V.
ABSTRACT
Objective: To assess the association between liver injury and the severity of Corona Virus Disease 2019 (COVID-19) disease. Methods: Articles including severe vs non-severe or dead vs surviving COVID-19 patients were identified by searching the electronic database including PubMed, Embase and the Cochrane Library database. The meta-analysis was carried out using software RevMan 5.3. A fixed- or random-effects model was used depending on the heterogeneity between studies. Furthermore, publication bias was evaluated by the visual inspection of funnel plot. Results: Thirty-six studies involving 7083 patients were taken into analysis. The incidence of patients with chronic liver disease was not significantly associated with an enhanced risk of severe COVID-19 (OR: 1.36, 95% CI: 0.89-2.07, P = .16). The total bilirubin (TB), lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were found to be obviously elevated in COVID-19 patients with severe group [TB: MD: 1.68, 95% CI: 1.17-2.19, P < .0001;LDH: MD: 122.66, 95% CI: 86.50-158.81, P < .0001;ALT: MD = 5.73, 95% CI (4.32, 7.14), P < .0001;AST: MD = 9.41, 95% CI (6.51, 12.31), P < .0001] and mortality group [TB: MD: 3.90, 95% CI: 2.63-5.18, P < .0001;LDH: MD: 246.30, 95% CI: 176.78-315.82, P < .0001;ALT: MD = 5.64, 95% CI (0.52, 10.75), P = .03;AST: MD = 12.93, 95% CI (4.95, 20.91), P = .002]. Albumin was significantly lower in COVID-19 patients with severe group (MD: -4.48, 95% CI: -6.51, -2.44, P < .0001) and mortality group (MD: -4.80, 95% CI: -5.94, -3.67, P < .0001). Based on visual inspection of funnel plots, no evidence of publication bias was found. Conclusions: According to our results, liver injury may be an important sign of COVID-19 associated to a severe form of disease, which can guide the clinicians in recognizing critically ill patients earlier and faster. However, due to the limitations of this study, more high-quality research is required.