MFPHMI Part I cheat sheet

Incidence rate = new cases / person-time at risk; attack rate = new cases / population at risk over a defined period.

Prevalence ≈ incidence × mean duration of disease (steady-state assumption); prevalence rises with longer survival or lower mortality.

Relative risk = incidence in exposed / incidence in unexposed; attributable risk = incidence in exposed − incidence in unexposed.

Population attributable fraction = Pe(RR−1) / [1 + Pe(RR−1)], where Pe is the prevalence of exposure.

Sensitivity = TP/(TP+FN); specificity = TN/(TN+FP); PPV depends on prevalence: PPV = sens·p / [sens·p + (1−spec)(1−p)].

Crude mortality comparison across populations requires age standardisation (direct or indirect) to remove confounding by age structure.

Herd immunity threshold = 1 − 1/R0; for R0 = 5 the threshold is 0.8 (80%).

Screening test criteria: important condition, accepted treatment, recognisable latent stage, suitable test, cost-effective, continuous case-finding.

Bradford Hill considerations include strength, consistency, temporality, biological gradient, plausibility; temporality is essential.

Standard error of the mean = s/√n; 95% CI for a mean ≈ mean ± 1.96·SE (large samples).

Type I error (α) = false positive rate; type II error (β) = false negative rate; power = 1 − β.

Sample size for a mean scales with (zα + zβ)²σ²/d²; halving the detectable difference d requires roughly 4× the sample.

Chi-square tests compare observed and expected frequencies in contingency tables; expected cell counts <5 require Fisher's exact test.

t-test compares two means; ANOVA compares three or more means; Mann-Whitney and Kruskal-Wallis are non-parametric analogues.

Pearson correlation r measures linear association (−1 to +1); r² is the proportion of variance explained.

Number needed to treat = 1/absolute risk reduction; NNT = 1/ARR where ARR = control event rate − treatment event rate.

Linear regression slope is change in outcome per unit change in predictor; logistic regression reports odds ratios.

p-value is the probability of data at least as extreme as observed given the null hypothesis is true; it is not the probability the null is true.

Basic reproduction number R0 = mean secondary cases per index case in a fully susceptible population; effective R = R0 × susceptible fraction.

Outbreak investigation steps: verify diagnosis, confirm outbreak, define cases, describe by person/place/time, generate hypothesis, control, communicate.

Incubation periods: measles 10–14 days, chickenpox 10–21 days, mumps 14–25 days, rubella 14–21 days, influenza 1–4 days.

Notifiable disease notification in the UK is a statutory duty on registered medical practitioners to the local proper officer (usually via UKHSA).

Case definitions in outbreaks use clinical, epidemiological and laboratory criteria; confirmed cases require laboratory evidence.

Contact tracing window for most respiratory viruses is from 48 hours before symptom onset until symptoms resolve.

Standard infection control precautions apply to all patients; transmission-based precautions (contact, droplet, airborne) are added for specific pathogens.

Vaccine efficacy = (ARU − ARV)/ARU × 100%, where ARU and ARV are attack rates in unvaccinated and vaccinated groups.

Post-exposure prophylaxis examples: hepatitis B immunoglobulin plus vaccine, varicella-zoster immunoglobulin, rabies vaccine plus immunoglobulin.

Ottawa Charter (1986) five action areas: build healthy public policy, create supportive environments, strengthen community action, develop personal skills, reorient health services.

Three health promotion approaches: educational (information), behavioural (lifestyle change), socio-environmental (structural change).

Precede-Proceed model phases: social assessment, epidemiological assessment, educational/ecological assessment, administrative/policy assessment, implementation, evaluation.

Stages of change (Prochaska & DiClemente): pre-contemplation, contemplation, preparation, action, maintenance, relapse.

Health Belief Model constructs: perceived susceptibility, severity, benefits, barriers, cues to action, self-efficacy.

Upstream interventions target social determinants; downstream interventions target individual behaviour; upstream generally has greater population impact.

Health literacy is the capacity to obtain, process and understand basic health information to make appropriate health decisions.

Social marketing uses commercial marketing principles (product, price, place, promotion) to promote health behaviour change.

Levels of prevention: primordial (prevent risk factor emergence), primary (prevent disease), secondary (early detection), tertiary (limit disability), quaternary (avoid overmedicalisation).

Screening programmes require a validated test, agreed recall interval, quality assurance and adequate follow-up and treatment pathways.

Equity vs equality: equity allocates resources according to need; equality allocates identical resources to all.

Health needs assessment covers epidemiological (need), comparative (utilisation) and corporate (perceived) approaches.

Quality in healthcare is often framed by the six dimensions: safe, effective, patient-centred, timely, efficient, equitable.

Donabedian model of quality: structure (resources), process (what is done), outcome (results).

NHS constitution principles include comprehensive care free at the point of use, access based on clinical need, and patient involvement.

Public health outcome frameworks track indicators across domains such as improving wider determinants, health improvement and health protection.

Allocative efficiency means distributing resources between programmes to maximise total health gain; technical efficiency means producing a given output at minimum cost.

Incidence rate = new cases / person-time at risk; attack rate = new cases / population at risk over a defined period.

Prevalence ≈ incidence × mean duration of disease (steady-state assumption); prevalence rises with longer survival or lower mortality.

Relative risk = incidence in exposed / incidence in unexposed; attributable risk = incidence in exposed − incidence in unexposed.

Population attributable fraction = Pe(RR−1) / [1 + Pe(RR−1)], where Pe is the prevalence of exposure.

Sensitivity = TP/(TP+FN); specificity = TN/(TN+FP); PPV depends on prevalence: PPV = sens·p / [sens·p + (1−spec)(1−p)].

Crude mortality comparison across populations requires age standardisation (direct or indirect) to remove confounding by age structure.

Herd immunity threshold = 1 − 1/R0; for R0 = 5 the threshold is 0.8 (80%).

Screening test criteria: important condition, accepted treatment, recognisable latent stage, suitable test, cost-effective, continuous case-finding.

Bradford Hill considerations include strength, consistency, temporality, biological gradient, plausibility; temporality is essential.

Standard error of the mean = s/√n; 95% CI for a mean ≈ mean ± 1.96·SE (large samples).

Type I error (α) = false positive rate; type II error (β) = false negative rate; power = 1 − β.

Sample size for a mean scales with (zα + zβ)²σ²/d²; halving the detectable difference d requires roughly 4× the sample.

Chi-square tests compare observed and expected frequencies in contingency tables; expected cell counts <5 require Fisher's exact test.

t-test compares two means; ANOVA compares three or more means; Mann-Whitney and Kruskal-Wallis are non-parametric analogues.

Pearson correlation r measures linear association (−1 to +1); r² is the proportion of variance explained.

Number needed to treat = 1/absolute risk reduction; NNT = 1/ARR where ARR = control event rate − treatment event rate.

Linear regression slope is change in outcome per unit change in predictor; logistic regression reports odds ratios.

p-value is the probability of data at least as extreme as observed given the null hypothesis is true; it is not the probability the null is true.

Basic reproduction number R0 = mean secondary cases per index case in a fully susceptible population; effective R = R0 × susceptible fraction.

Outbreak investigation steps: verify diagnosis, confirm outbreak, define cases, describe by person/place/time, generate hypothesis, control, communicate.

Incubation periods: measles 10–14 days, chickenpox 10–21 days, mumps 14–25 days, rubella 14–21 days, influenza 1–4 days.

Notifiable disease notification in the UK is a statutory duty on registered medical practitioners to the local proper officer (usually via UKHSA).

Case definitions in outbreaks use clinical, epidemiological and laboratory criteria; confirmed cases require laboratory evidence.

Contact tracing window for most respiratory viruses is from 48 hours before symptom onset until symptoms resolve.

Standard infection control precautions apply to all patients; transmission-based precautions (contact, droplet, airborne) are added for specific pathogens.

Vaccine efficacy = (ARU − ARV)/ARU × 100%, where ARU and ARV are attack rates in unvaccinated and vaccinated groups.

Post-exposure prophylaxis examples: hepatitis B immunoglobulin plus vaccine, varicella-zoster immunoglobulin, rabies vaccine plus immunoglobulin.

Ottawa Charter (1986) five action areas: build healthy public policy, create supportive environments, strengthen community action, develop personal skills, reorient health services.

Three health promotion approaches: educational (information), behavioural (lifestyle change), socio-environmental (structural change).

Precede-Proceed model phases: social assessment, epidemiological assessment, educational/ecological assessment, administrative/policy assessment, implementation, evaluation.

Stages of change (Prochaska & DiClemente): pre-contemplation, contemplation, preparation, action, maintenance, relapse.

Health Belief Model constructs: perceived susceptibility, severity, benefits, barriers, cues to action, self-efficacy.

Upstream interventions target social determinants; downstream interventions target individual behaviour; upstream generally has greater population impact.

Health literacy is the capacity to obtain, process and understand basic health information to make appropriate health decisions.

Social marketing uses commercial marketing principles (product, price, place, promotion) to promote health behaviour change.

Levels of prevention: primordial (prevent risk factor emergence), primary (prevent disease), secondary (early detection), tertiary (limit disability), quaternary (avoid overmedicalisation).

Screening programmes require a validated test, agreed recall interval, quality assurance and adequate follow-up and treatment pathways.

Equity vs equality: equity allocates resources according to need; equality allocates identical resources to all.

Health needs assessment covers epidemiological (need), comparative (utilisation) and corporate (perceived) approaches.

Quality in healthcare is often framed by the six dimensions: safe, effective, patient-centred, timely, efficient, equitable.

Donabedian model of quality: structure (resources), process (what is done), outcome (results).

NHS constitution principles include comprehensive care free at the point of use, access based on clinical need, and patient involvement.

Public health outcome frameworks track indicators across domains such as improving wider determinants, health improvement and health protection.

Allocative efficiency means distributing resources between programmes to maximise total health gain; technical efficiency means producing a given output at minimum cost.