However, evidence of a relationship between cannabis use and cognitive impairment is confounded by concomitant use of tobacco.
Although several tests aiming to assess emotions exist (see, for example, [29]), these have often been confounded by concomitant cognitive processes, such as appraisal [30], [31], decision making [32], or memory [33], [34].
However, in this study, 10-weeks treatment with TTM induced significant lowering of circulating ceruloplasmin levels, raising the possibility that the reported findings could have been confounded by concomitant copper deficiency, as signaled by marked lowering of serum ceruloplasmin levels.
However, the results from these studies are confounded by concomitant weight loss, so it is unclear whether the improvements in IS occurred because of weight loss or because of the insulin-sensitizing properties of ginsenosides.
However, two of the three randomised trials of lower fat intake are confounded by concomitant weight loss [ 57, 58] and the one study without weight loss showed no effect of reduction of fat intake on breast cancer relapse after surgery [ 59].
The packages of August 2011 and July 2012 were taken under episodes of fiscal stress (risk premium at historical heights), and therefore their effects on GDP could be confounded by the effect of the concomitant financial turmoil.
Notably, drug discontinuation may ensue from more than one of the aforementioned reasons and may also be confounded by 'mixed response' the latter implies the concomitant presence of both treatment response and reasons for drug interruption/discontinuation.
If not, the estimates will be confounded by omitted variables.
Studies of surgical outcomes can be confounded by operative complexity.
