Nine studies assessed treatment effects by adjusting confounders, thus they were low risk of confounding bias.
To reduce the risk of confounding factors we adjusted statistically for all plausible confounders.
But Anderson was aware that he ran the risk of confounding the public's expectations.
Are you an artist with a spectacularly ambitious idea that runs the risk of confounding both the critics and your fans?
The retrospective studies were all judged to be at high risk of confounding variables.
Calculating workload/staffing ratios on a unit basis also minimized the risk of confounding by severity of illness.
First, because it was conducted as a retrospective cohort study in a single center, there is a potential risk of confounding variables and selection bias.
2+ Well-conducted case-control or cohort studies with a low risk of confounding, bias or chance and a moderate probability that the relationship is causal.
2- Case-control or cohort studies with a high risk of confounding, bias or chance and a significant risk that the relationship is not causal.
The included studies compared two different levels of PEEP using the same tidal volume in the two arms, thereby minimizing the risk of confounding effects of different tidal volume sizes.
2++ High-quality systematic reviews of case control or cohort studies or high-quality case-control or cohort studies with a very low risk of confounding, bias or chance and a high probability that the relationship is causal.
