However, in real data analysis, there is possibility that a true effect failed to be identified at the initial step given a weak exposure-response association will be missed in the regression model.
However, the interpretation of epidemiological evidence has been complicated by weak exposure assessments and limited case numbers.
Non-existence of the risk, negative confounding, weak exposure or low study-power may explain the negative findings.
Properly conducted, biomonitoring could also help deliver valuable evidence for epidemiologic studies, which are frequently plagued by weak exposure data.
Generally, DiD has proved to have surprisingly high power to detect effects even of quite weak exposures 66.
It is assumed that this reaction is specific for cells expressing an active cytochrome c oxidase, because strains lacking such an enzyme usually show only a weak reaction upon exposure to TMPD, which can be used as electron donor instead of cytochrome c by terminal oxidases [50].
According to the clinical trials, there was a weak association between exposure to ultrasonography and non-right handedness in boys (OR 1.26, 95% CI 1.03-1.54) and a slight decrease in mean neonatal length (WMD −0.26 cm, CI −0.45, −0.07) and head circumference (WMD −0.15 cm, CI-0.29, −0.01).
Conversely, it was shown that miR-34a and miR-21 had major effects on glucose stimulated insulin secretion (GSIS) through the regulation of VAMP2 expression, a molecule involved in insulin granule exocytosis, and of Rab3a (GTPase) and that this effect can be mimicked by a weak and short exposure to cytokines.
For those having started work 1955 1964 (402 cases, 466 049 person-years, mean exposure 104 WLM) there was only a weak effect of exposure-rate.
This reconstruction was observed no sooner than 60 min after the onset of weak light exposure.
In occupational epidemiology, classification of exposure as ever versus never and duration have often been the only available proxies of the actual exposures and are typically cruder and weaker exposure scales than cumulative or intensity-weighted metrics.
