Let A (0) represent exposure (breast-feeding) at time 0 (using values in parentheses to represent time), B (2) outcome (allergy) at time 2, and C (0) a confounding variable
(infant weight) occurring temporally before A (0) that has a direct causal effect on both A (0) and B (2); note that, in Figure 1a, A (0) has no causal effect on B (2).
are any other variable that also has an effect on your dependent variable.
Race and overall GPA were found to be confounding variables
and their effects were therefore statistically removed in analyses.
The 2 measures of patient-centeredness were correlated with the outcomes of visits, adjusting for the clustering of patients by physician and controlling for confounding variables
Dr Glaser points out potential confounding variables
that, if not addressed, would warrant a more limited and refined interpretation of the results.
The researchers noted previous evidence that a lower prevalence of breastfeeding among blacks, compared with other ethnicities, might be a confounding variable
The researchers noted previous evidence that a lower prevalence of breastfeeding in blacks, compared with other ethnicities, might be a confounding variable
, but they said that the overall presence of a protective effect of breast-feeding against type 2 diabetes suggests that all populations might benefit it.
After censoring deaths within 60 days of starting EECP as a potential confounding variable
, researchers report the 1-year mortality in EECP completers as 4.
The other first-stage model relates a putative confounding variable
And many more of the nurses had a history of oral contraceptive use, a possible confounding variable
, than the Framingham women.
OC use therefore may represent a confounding variable
in previous sleep studies that compare healthy and depressed patients, said Dr.
One problem with some of the previous data, however, was that a possible confounding variable
was not controlled: The injury or illness itself may have caused people to become depressed.