A sensitivity analysis determine the magnitude of a potential unmeasured confounder
that would need to be present to materially alter the conclusions of a study
5] constituents, adjusted by community-level confounders
and previous-year P[M.
On the basis of a priori substantive knowledge, we created a directed acyclic graph and determined a minimum sufficient conditioning set of confounders
(VanderWeele and Robins 2009).
After adjustment for age and season, these variables often acted as confounders
or effect modifiers, but in general the associations remained significant.
If an implausibly strong hypothetical unmeasured confounder
is required to bring the observed OR "back" to 1, then this allows the analyst to be more confident that the observed association is more likely to be causal.
Many papers examining the effect of heat on mortality controlled for ozone as a confounder
without further discussion of the motivation for such designation or investigation of the quantitative effect of including ozone in their statistical models (e.
This could occur when the correlation between a confounder
and exposure are magnified at extreme values of the confounder
's distribution, such as if age were the confounding variable and daily medication use the exposure.
adjustment, lean multivitamin users had a 71% reduction in pre-eclampsia risk compared with lean non-users.
Although breast-feeding did not appear to be an important confounder
in our data, we agree with Thirea that this factor needs to be considered in studies of prenatal and early life environmental exposures and neurodevelopment.
Boosting may at times produce large reactions and in all serial TB studies will be a potential confounder
It's a real confounder
in all these studies," said Dr.
Health care utilization was higher among those with RA, which was a slight confounder
in this study despite the attempt to control for number of visits: Even after adjustment, there was still a significant residual effect tor number of visits, with an odds ratio of 1.
The study was well performed and reported, except for the omission of two possible confounders
related to an individual's drinking water--magnesium content and total hardness.
Sensitivity analyses to assess the possible impact of unmeasured confounders
make it highly unlikely that any influenced the result of the TREAT-AF Study.
Researchers found that after adjusting for various confounders
such as age, sex, body weight, smoking, hypnotics, and physical activity, subjects with persistent insomnia were 58% more likely to die during the study than subjects with no insomnia and that mortality was cardiovascular- rather than cancer-related.