Public Health Flashcards
Define incidence
Number of new cases of a disease/condition in a population per unit time
Define prevalnce
Number of existing cases of a disease/condition in a population at a given point in time
What are the 5 stages of change?
Pre-contemplation Contemplation Preparation Action Maintenance
What is the aim of a primary intervention?
It aims to prevent the onset of a disease and involves interventions that are applied before any evidence of disease is present e.g. vaccines
What is the aim of a secondary intervention?
Detection of disease in earliest stages before symptoms are present and intervening to slow, stop or reverse disease progression e.g. breast cancer screening
What is the aim of a tertiary prevention?
Interventions designed to arrest the progress of established disease and minimise its negative consequences
What is screening?
A process which identifies apparently well individuals who may be at increased risk of developing a condition
What is selection bias?
A systematic error in selection/allocation of study participants
What is screening?
A process which identifies apparently well individuals who may be at increased risk of developing a condition, in the early stages of a condition so that intervention can alter the disease course thereby reducing morbidity and mortality
What is a true negative?
A result that is negative and the patient has not got the disease
What is a false positive?
A positive result but the patient does not have the disease
What is a false negative?
A negative result but the patient does have the disease
Define sensitivity
Ability of a test to correctly identify those with the disease
A/A+C
Define specificity
Ability of a test to correctly identify those without the disease
B/B+D
Define positive predicted value
The proportion of the positive results that are true positives
A/A+B
Define negative predicted value
The proportion of the negative results that are true negatives
D/D+C
What are the limitations of using PSA as a screening test?
Raised in BPH, prostatitis, after ejaculation, bike riding
What are the limitations of using a D-dimer to detect PE?
It can be raised due to other conditions
What is absolute risk?
The risk of developing risk over a time period
What is relative risk?
Risk of getting a disease in an exposed group compared to an unexposed group. It’s a ratio so has no units
What’s attributable risk?
AKA absolute risk reduction
Rate of disease in exposed that may be attributed to exposure
Incidence in exposed - incidence in unexposed
Define number needed to treat
The number of people need to be treated for one person to benefit
NNT= 1/ARR
Define a never event
A serious, largely avoidable patient safety event which should not occur if the available preventative measures have been implemented
Give some examples of a never event
Wrong patient Wrong site surgery Wrong drug dose Foreign body retained Mental health: escape of transfer patient ABO incompatibility