Risk and Effect Measures
Calculate and communicate treatment benefit and harm using absolute as well as relative measures.
How to prepare for the MRCGP AKT
Build broad current clinical knowledge, then rehearse evidence interpretation and the ethical, administrative, statutory and regulatory decisions unique to UK primary care.
Core concepts
Concept 1
Absolute and relative risk, risk ratio, risk difference, NNT, NNH, confidence intervals and forest plots.
Exam cue: Name the exact decision and time point before reviewing the options.
Concept 2
Build a two-group event table, keep the time horizon visible and express results in patient-meaningful terms.
Exam cue: Separate the decisive clinical, numerical or governance fact from plausible background detail.
Concept 3
Check direction, denominator, baseline risk and uncertainty before recommending or communicating an intervention.
Exam cue: Choose the safest proportionate action for UK general practice and include follow-up or escalation where relevant.
Concept 4
Apply current UK guidance and patient context while accepting that the most appropriate answer may be no investigation, prescription or referral.
Risk pitfalls and guardrails
Presenting a large relative effect without the absolute difference, population, time period or confidence interval.
Guardrail: Do not choose a familiar fact or technically possible action when the stem asks for the most appropriate current UK primary-care decision.
Recalling a guideline fragment without checking whether it applies to this patient, population or administrative context.
Guardrail: Do not choose a familiar fact or technically possible action when the stem asks for the most appropriate current UK primary-care decision.
Choosing an action that is possible but not the most appropriate option at the stated point in care.
Guardrail: Do not choose a familiar fact or technically possible action when the stem asks for the most appropriate current UK primary-care decision.
Memory anchors
Risk and Effect Measures: scope
Absolute and relative risk, risk ratio, risk difference, NNT, NNH, confidence intervals and forest plots.
Risk and Effect Measures: primary-care lens
Build a two-group event table, keep the time horizon visible and express results in patient-meaningful terms.
Risk and Effect Measures: safety boundary
Check direction, denominator, baseline risk and uncertainty before recommending or communicating an intervention.
Risk and Effect Measures: common trap
Presenting a large relative effect without the absolute difference, population, time period or confidence interval.
Risk and Effect Measures: AKT decision sequence
Define the exact UK general-practice problem, identify the decisive evidence and safety issue, then choose the most appropriate action for this point in care.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
Over five years, 12% of controls and 8% of treated patients have a stroke. What is the absolute risk reduction?
A treatment reduces event risk from 20% to 15%. What is the relative risk?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
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