1. Bias in clinical research
G. Tripepi, K.J. Jager, F.W. Dekker, C. Wanner, C. Zoccali 
Kidney International 
Volume 73, Issue 2, Pages (January 2008)
DOI: /sj.ki
Copyright © 2008 International Society of Nephrology Terms and Conditions

2. Figure 1 A hypothetical example of incidence-prevalence bias.
Kidney International  , DOI: ( /sj.ki )
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3. Figure 2
A hypothetical example of funnel plot. Left panel: the shape of the plot suggests that smaller studies indicating a worse outcome with the treatment being tested, might not have been reported (just one study where treatment produced worse outcome) (publication bias); right panel: there are smaller studies showing either beneficial or no beneficial effects of the treatment (no publication bias).
Kidney International  , DOI: ( /sj.ki )
Copyright © 2008 International Society of Nephrology Terms and Conditions

4. Figure 3
An example of regression to the mean phenomenon. The two individuals in the top category of BP level have higher systolic pressure at the first visit than at the second, while the two individuals in the bottom category have lower systolic pressure at the first visit than at the second.
Kidney International  , DOI: ( /sj.ki )
Copyright © 2008 International Society of Nephrology Terms and Conditions

5. Figure 4 A hypothetical example of lead-time bias.
Kidney International  , DOI: ( /sj.ki )
Copyright © 2008 International Society of Nephrology Terms and Conditions

6. Kidney International 2008 73, 148-153DOI: (10.1038/sj.ki.5002648)
Copyright © 2008 International Society of Nephrology Terms and Conditions

7. Kidney International 2008 73, 148-153DOI: (10.1038/sj.ki.5002648)
Copyright © 2008 International Society of Nephrology Terms and Conditions

8. Kidney International 2008 73, 148-153DOI: (10.1038/sj.ki.5002648)
Copyright © 2008 International Society of Nephrology Terms and Conditions

9. Kidney International 2008 73, 148-153DOI: (10.1038/sj.ki.5002648)
Copyright © 2008 International Society of Nephrology Terms and Conditions

10. Kidney International 2008 73, 148-153DOI: (10.1038/sj.ki.5002648)
Copyright © 2008 International Society of Nephrology Terms and Conditions