Research Methods & Evidence-Based Practice Flashcards

A renal dietitian is conducting a mixed-methods study on dietary adherence barriers in hemodialysis patients. The qualitative component involves thematic analysis of patient interviews. What is the primary advantage of including qualitative data in this renal nutrition study?

Answer: It provides in-depth understanding of patients' lived experiences and contextual barriers

Qualitative methods capture nuanced patient perspectives, motivations, and contextual factors that quantitative measures alone cannot reveal.

In a pragmatic RCT on MNT delivery for CKD patients, external validity refers to:

Answer: The degree to which study results can be generalized to real-world clinical practice

External validity (generalizability) is the extent to which study findings apply to populations and settings beyond the study sample.

A researcher conducting a systematic review on dietary patterns and CKD mortality uses a PRISMA flow diagram. What is the primary purpose of this diagram?

Answer: To document and transparently report the study selection process from identification to inclusion

The PRISMA flow diagram transparently records the number of studies identified, screened, assessed for eligibility, and included at each stage of the review process.

When critically appraising a prospective cohort study on dietary phosphorus and cardiovascular outcomes in CKD, which of the following represents a threat to internal validity?

Answer: Phosphorus intake was estimated using an unvalidated food frequency questionnaire

Using an unvalidated dietary assessment tool introduces measurement error, threatening the internal validity by misclassifying exposure levels.

A renal dietitian wants to assess whether a new protein-restricted diet app improves dietary adherence in CKD patients compared to standard counseling using a crossover design. A key advantage of this design is:

Answer: Each participant serves as their own control, reducing variability due to individual differences

In a crossover design, within-subject comparisons control for individual differences, increasing statistical efficiency and reducing required sample size.

A meta-analysis on omega-3 supplementation in dialysis patients reports a pooled relative risk (RR) of 0.78 (95% CI: 0.65–0.94) for cardiovascular events. How should this confidence interval be interpreted?

Answer: If the study were repeated 100 times, 95 of the resulting intervals would contain the true RR

A 95% CI means that 95% of identically constructed intervals from repeated sampling would contain the true population parameter, not that there is a 95% chance this specific interval does.

A renal dietitian is evaluating a study protocol that includes a validated 24-hour dietary recall collected three times over one month in CKD patients. Compared to a single 24-hour recall, this repeated-measures approach primarily improves:

Answer: Estimation of usual dietary intake by capturing day-to-day variation

Multiple 24-hour recalls across different days better capture habitual dietary intake by accounting for within-person variation in food consumption patterns.