CSR Research Methods & Evidence-Based Practice 2

Question 1

In a randomized controlled trial evaluating a low-phosphorus diet in CKD patients, the primary outcome is serum phosphorus reduction. What is the most appropriate method to account for dropouts and maintain the integrity of the original randomization?

Accepted Answer

Intention-to-treat analysis

Answer

Intention-to-treat analysis preserves randomization and prevents bias introduced by selective dropout, making it the gold standard for RCT primary outcomes.

Question 2

A renal dietitian wants to evaluate the strength of a study's causal claim that dietary protein restriction slows GFR decline. Which study design provides the highest level of evidence for causality?

Accepted Answer

Systematic review of randomized controlled trials

Answer

A systematic review of RCTs sits at the top of the evidence hierarchy and provides the strongest basis for causal inferences.

Question 3

When appraising a meta-analysis on potassium intake in dialysis patients, a renal dietitian notices an I² statistic of 85%. How should this be interpreted?

Accepted Answer

There is high heterogeneity among the included studies

Answer

An I² of 75% or higher indicates substantial to considerable heterogeneity, suggesting the studies are measuring the intervention effect under very different conditions.

Question 4

A dietitian is designing a study comparing intradialytic parenteral nutrition (IDPN) versus oral supplements on albumin levels. Which blinding strategy is most feasible in this setting?

Accepted Answer

Single-blind (only outcome assessor blinded)

Answer

Because patients can identify their nutritional delivery route, blinding only the outcome assessor (single-blind) is the most feasible rigorous option.

Question 5

In a renal nutrition study, researchers report a statistically significant result (p=0.03) but a mean serum phosphorus reduction of only 0.2 mg/dL. What concept best explains why this finding may not be clinically meaningful?

Accepted Answer

Difference between statistical and clinical significance

Answer

Statistical significance indicates a result unlikely due to chance, but clinical significance requires the effect size to be large enough to matter in patient care.

(CSR) Board Certified Specialist in Renal Nutrition Practice Test

(CSR) Board Certified Specialist in Renal Nutrition Practice Test

CSR Research Methods & Evidence-Based Practice 2