Uncertainty about the potential adverse effects and causation highlights the need for investigation of a broader range of maternal and perinatal effects in studies providing higher levels of evidence, such as randomised controlled trials (RCTs).
There is undoubtedly a very large range of disturbing effects, and causation is most of the time difficult to establish because time between cancer initiation and its detection is usually long.
1990 Sobel, M. E. "Effect Analysis and Causation in Linear Structural Equation Models". Psychometrika 55: 49555555
An interplay of a healthy cohort effect and reversed causation bias due to prodromal symptoms impedes detection of a possible association with dementia and Parkinson disease.
With regard to dementia, an interplay of a healthy cohort effect and reversed causation bias due to prodromal symptoms impedes detection of a possible association, although identification of the factors that contribute to the healthy cohort would be of interest for determining the aetiology of dementia.
In a case control study, which reported a dose-dependent association between paracetamol use and asthma, a progressively greater risk in those with more severe disease was noted, suggesting an effect on causation and severity of the disease.
However, two studies from Sweden and Finland, respectively show evidence for a selection effect; individuals on sick leave or with poor health have an elevated risk of future unemployment., Thus, there is evidence in the literature of both a causation effect and a selection effect when explaining the relationship between unemployment and ill-health.
As described above, the criteria for making reasonable inferences of association of exposure to benzene and causation of toxic effect are supported by the Bradford Hill guidelines (Table 1).
Almost all, in the headers or the articles beneath, attributed their large-font claims to the same study, despite reaching contradicting slants, conflating correlation and causation, and exaggerating the effect size.
