FPGEE Biostatistics 5

Question 1

In a pharmacoeconomic study, incremental cost-effectiveness ratio (ICER) is calculated as $80,000 per QALY. Using the commonly cited US willingness-to-pay threshold, how should this be classified?

Accepted Answer

Borderline cost-effective

Answer

Highly cost-effective

Answer

Not cost-effective

Answer

Dominant strategy

Question 2

In a cohort study, person-years are used as the denominator for incidence rates. Why is this approach used?

Accepted Answer

It accounts for varying lengths of follow-up among participants

Answer

It increases statistical power

Answer

It corrects for confounding variables

Answer

It normalizes for differences in baseline risk

Question 3

A publication reports a forest plot in which most individual study confidence intervals overlap zero, but the pooled diamond does not touch zero. What is the most accurate interpretation?

Accepted Answer

The pooled analysis has sufficient power to detect a statistically significant overall effect

Answer

The meta-analysis result should be ignored due to heterogeneity

Answer

Each individual study confirms the treatment works

Answer

The funnel plot shows publication bias

Question 4

A researcher wants to assess agreement between two pharmacists measuring pill-cutting accuracy using a continuous scale. Which statistical method is most appropriate?

Accepted Answer

Bland-Altman plot and limits of agreement

Answer

Pearson correlation coefficient

Answer

Kappa coefficient

Answer

Intraclass correlation coefficient only

Question 5

Cox proportional hazards regression produces a hazard ratio (HR) of 0.60 for a new antifungal vs. placebo (95% CI: 0.40–0.89). How should this be interpreted?

Accepted Answer

The new drug reduces the instantaneous risk of the event by 40% at any given time

Answer

The new drug increases the event hazard by 40%

Answer

Patients on the new drug survive 60% longer on average

Answer

The result is not statistically significant

Question 6

Which study design provides the strongest evidence for establishing causality between a drug exposure and an outcome?

Accepted Answer

Randomized controlled trial

Answer

Prospective cohort study

Answer

Systematic review of case-control studies

Answer

Well-designed cross-sectional survey

Question 7

In logistic regression used to predict a binary outcome (adverse drug reaction: yes/no), the model output is best expressed as:

Accepted Answer

An odds ratio derived from the exponentiated regression coefficient (e^β)

Answer

A regression coefficient (β) directly interpreted as probability

Answer

A hazard ratio comparing event times

Answer

A correlation coefficient between predictors and the outcome