title: Balancing the Evidence: How to Reconcile the Results of Observational Studies vs. Randomized Clinical Trials in Dialysis.
abstract: Because large randomized clinical trials (RCTs) in dialysis have been relatively scarce, evidence-based dialysis care has depended heavily on the results of observational studies. However, when results from RCTs appear to contradict the findings of observational studies, nephrologists are left to wonder which type of study they should believe. In this editorial, we explore the key differences between observational studies and RCTs in the context of such seemingly conflicting studies in dialysis. Confounding is the major limitation of observational studies, whereas low statistical power and problems with external validity are more likely to limit the findings of RCTs. Differences in the specification of the population, exposure, and outcomes can also contribute to different results among RCTs and observational studies. Rigorous methods are required regardless of what type of study is conducted, and readers should not automatically assume that one type of study design is superior to the other. Ultimately, dialysis care requires both well-designed, well-conducted observational studies and RCTs to move the field forward.
authors.affiliation: Department of Medicine, Division of Hypertension and Nephrology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California. jshen@labiomed.org.|Department of Medicine, Division of Nephrology, David Geffen School of Medicine at UCLA, Los Angeles, California. jshen@labiomed.org.
authors.forename: Jenny I
authors.initials: JI
authors.lastname: Shen
authors.affiliation: Department of Medicine, Division of Nephrology, David Geffen School of Medicine at UCLA, Los Angeles, California.
authors.forename: Erik L
authors.initials: EL
authors.lastname: Lum
authors.affiliation: Department of Medicine, Division of Nephrology, Stanford University School of Medicine, Stanford, California.
authors.forename: Tara I
authors.initials: TI
authors.lastname: Chang
mesh_terms: D019317:Evidence-Based Medicine; D006801:Humans; D064887:Observational Studies as Topic; D016032:Randomized Controlled Trials as Topic; D006435:Renal Dialysis; D012107:Research Design