Research & Evidence-Based Practice Flashcards

A radiography study compares image quality between two CR systems. Which statistical test is most appropriate to compare two independent group means?

Answer: Independent samples t-test

The independent samples t-test compares the means of two independent groups. It is appropriate when the data are continuous (e.g., image quality scores) and normally distributed with two groups being compared.

Which of the following research designs is best suited for establishing a cause-and-effect relationship between an intervention and an outcome?

Answer: Randomized controlled trial (RCT)

The RCT is the gold standard for establishing causality. Random assignment to treatment or control groups controls for confounding variables, allowing the researcher to attribute observed differences in outcomes to the intervention.

Interrater reliability in a radiography image quality study measures:

Answer: The degree of agreement between two or more independent evaluators rating the same images

Interrater reliability (often measured with Cohen's kappa or ICC) quantifies how consistently different evaluators rate the same images. High interrater reliability indicates the rating scale is objective and reproducible.

The concept of 'external validity' in research refers to:

Answer: The degree to which study findings can be generalized to other populations and settings

External validity (generalizability) refers to how well the study findings apply beyond the specific sample and setting studied. A study with high external validity can inform practice in diverse patient populations and healthcare settings.

A systematic review of radiographic positioning studies concludes that oblique projections of the cervical spine provide no additional diagnostic information over standard AP and lateral views in trauma patients. This finding should cause a radiographer to:

Answer: Consider revising the departmental protocol based on the evidence, in consultation with the radiologist

Evidence-based practice requires considering high-quality evidence (systematic review) in context — consulting with the radiologist and following a proper protocol review process before changing practice, rather than ignoring evidence or making unilateral changes.

In a study examining radiation dose from chest CT, 'sensitivity' of a dose-reduction technique refers to:

Answer: The technique's ability to detect true positives (pathological findings) without missing diagnoses

Sensitivity is the ability of a diagnostic test or technique to correctly identify true positives — detecting disease (or pathological findings) when it is present. A dose-reduced protocol should maintain high sensitivity so diagnoses are not missed.