Impact of quality of research on patient outcomes in the Institute of Medicine 2013 report on dietary sodium.

The 2013 Institute of Medicine report entitled "Sodium Intake in Populations: Assessment of Evidence" found inconsistent evidence of health benefit with dietary sodium intake <2300 mg/d. Different studies reported benefit and harm of population dietary intake <2300 mg/d. The Institute of Medicine committee, however, did not assess whether the methodology used in each of the studies was appropriate to examine dietary sodium and health outcomes. This review investigates the association of methodological rigor and outcomes of studies in the Institute of Medicine report. For the 13 studies that met all methodological criteria, nine found a detrimental impact of high sodium consumption on health, one found a health benefit, and in three the effect was unclear (P = .068). For the 22 studies that failed to meet all criteria, 11 showed a detrimental impact, four a health benefit, and seven had unclear effects from increasing dietary sodium (P = .42).