MJDF Dental Public Health & Evidence-Based Dentistry 3

Question 1

What is the Cochrane Collaboration and its relevance to dental practice?

Accepted Answer

An independent non-profit organisation producing high-quality systematic reviews — Cochrane Oral Health publishes reviews directly relevant to clinical dentistry

Answer

Cochrane is the internationally recognised source of high-quality systematic reviews; Cochrane Oral Health group produces reviews on clinical questions directly applicable to dental practice, supporting evidence-based decision-making.

Question 2

What is the definition of 'sensitivity' of a diagnostic test?

Accepted Answer

The proportion of those who truly have the disease who test positive — TP/(TP+FN) — the test's ability to detect true disease

Answer

Sensitivity = TP/(TP+FN) — a highly sensitive test correctly identifies most true disease cases; a low-sensitivity test misses cases (false negatives). High sensitivity is important when missing disease would be harmful.

Question 3

What is 'specificity' of a diagnostic test?

Accepted Answer

The proportion of disease-free people who correctly test negative — TN/(TN+FP) — the test's ability to exclude disease

Answer

Specificity = TN/(TN+FP); a highly specific test correctly excludes disease in people who do not have it, minimising false positives. High specificity is important when a false positive would lead to harmful overtreatment.

Question 4

What is the Hawthorne effect in dental research?

Accepted Answer

Participants modify their behaviour because they know they are being observed — potential source of bias in dental clinical trials

Answer

The Hawthorne effect is a form of reactivity bias where study participants alter their behaviour (e.g., improving oral hygiene) simply because they know they are being studied, potentially inflating intervention effects.

Question 5

What is the purpose of randomisation in a clinical trial?

Accepted Answer

Distribute known and unknown confounding variables equally between groups, reducing selection bias — allowing causality to be inferred

Answer

Random allocation ensures that both measured and unmeasured confounders are distributed between intervention and control groups by chance, making the groups comparable at baseline and allowing causal inference from the results.

MJDF Part 1 Practice Test

MJDF Part 1 Practice Test

MJDF Dental Public Health & Evidence-Based Dentistry 3