In particular, the causal direction of an edge is generally not statistically identifiable, i.e., cannot be inferred as a statistical parameter, even from an unlimited amount of non-time series observational mRNA expression data.
Our study was single-centre and observational in nature and all associations cannot be inferred to have causal relationships.
For instance, causal inferences cannot be inferred based on the data.
While causal inference cannot be inferred, this study provides no indication that media attention preceded increasing trends in ILI incidence and influenza virus detections as reported in five surveillance systems during the pandemic period.
Therefore, the observed relationships between OA pain and productivity should be considered associative rather than causal, since direct causality cannot be inferred regarding the OA pain as a source of lost productivity, especially given that workers with OA pain were characterized by a significantly greater comorbidity burden than workers without OA pain.
25 A causal relation cannot be inferred from our results though, and the issue of reverse causality remains a concern.
Although directionality cannot be inferred from our analysis, previous work using causal modelling (Hare et al., 2011) highlights ventromedial PFC as being confluence of valuation signals that receives ventral striatum and dorsolateral PFC inputs.
In Figure 3, we do not specify the directionality of causal influences in this schema, as this cannot be inferred from the PPI method alone.
