All co-medication will be recorded and in analyses used as possible confounder or effect modifier.
We also did not have any information about the treatment that the participants received for their colorectal cancer, so were not able to investigate its role as a possible confounder or effect modifier.
For assessment of the issue of hypertension as a possible confounder for the effects of OSA on renal function, a cross-sectional study of 62 untreated hypertensive patients with OSA matched to 70 hypertensive patients without OSA found that albuminuria was 57% greater in patients with OSA versus those without and that albuminuria correlated with AHI and OSA severity (30).
Further, we adjusted our analyses for a variety of possible confounders and effect modifiers to avoid any potential effects of differential distribution of such variables among participants and non-participants.
The univariate associations between cadmium and kidney effect markers as well as those with possible confounders and effect modifiers are shown in Table 2. Cadmium in both blood and urine was associated with all kidney effect markers except serum creatinine and urinary calcium, which were not included in further analysis.
In considering all possible confounders and effect modifiers (age, physical activity, BMI, and hormone replacement therapy) in the model which made use of a diffuse normal prior distribution, the estimate for OR (Model 1) is 0.67.
Possible confounders and effect modifiers were measured by questionnaire.
The data are adjusted for possible confounders and effect modifiers (age, sex, type of cancer).
An additional limitation is that information on possible confounders or effect modifiers is not complete.
Next, multivariate logistic regression modelling, including genotypes, cumulative asbestos exposure, possible confounders, or effect modifiers, was employed.
