HaDPop Flashcards
How do you calculate total period fertility rate?
Sum of all age specific fertility rates
How is standardised mortality ratio calculated?
Observed deaths/expected x 100
How is incidence rate calculated>
Cases / (persons x years)
How are error factors calculated?
e^ 2 x (sq root of 1/observed event)
How are confidence intervals calculated?
Lower = value/error factor Upper = value x error factor
What are two types of selection bias?
Systematic error in how two groups were collected.
Allocation bias
Healthy worker effect
How is odds ratio calculated?
(exposed cases x unexposed controls) / (unexposed cases x exposed controls)
What is the null hypothesis when talking about an odds ratio?
1
What type of studies use odds ratios?
Case control studies
What is meant by the cause effect relationship in epidemiology?
Disease results from interplay between host, environment and agent.
A cause is an exposure or factor that increases the probability of disease.
Exposures don’t have to be necessary or sufficient to be a cause
What are the bradford hill criteria?
Strength of association Specificity of association Biology plausability Dose response Consistency of association Temporal sequence Reversibility Coherence of theory Analogy
What are 2 assumptions of epidemiology?
Disease doesn’t happen at random
Disease has causal and preventable factors that can be identified through systematic investigation
What is a clinical trial?
Any form of planned experiment that involves patients and plans to identify the most appropriate method of treatment for future patients with a given condition
What is meant by efficacy?
The ability of a healthcare intervention to improve the health of a particular group under specific conditions
What are 3 characteristics of a good clinical trial?
Fair
Reproducible
Controlled (ie uses controls)
What are some reasons for differences in otucomes between different patient groups in clinical trials?
Chance
Patient knows type of treatment
Assessor knows type of treatment
Treating clinician knows type of treatment
One treatment is more effective than another
Why do pre-defined outcomes need to be set for clinical trials?
To agree criteria for measurement and assessment of outcomes
To prevent repeated analyses
To give protocol for data collection
How do we minimise losses to follow up?
Make follow up practical, convenient and simple
Be honest about commitment
Avoid coercion or inducements
Maintain contact with participant
What is meant by clinical equipoise?
There’s reasonable uncertainty or genuine ignorance of the better treatment of intervention
What is meant be a trial being scientifically robust?
That a trial can be judged scientifically either by looking at what’s actually being researched or by looking at the safety and ethics of the trial
What is classed as ethical recruitment?
That there’s no inappropriate inclusion of communities unlikely to benefit from results, participants with higher risk of harm than benefit, participants likely to be excluded from analysis
And no inappropriate exclusion of people who differ from a homogenous group, people who are difficult to gain valid consent from
What factors are need for consent to be valid?
Knowledgeable informant Appropriate information Informed participant Competent decision maker Legitimate authoriser Voluntariness
What is a systematic review?
Overview of primary studies that used explicit and reproducible methods. Involves a systematic literature search then an appraisal and synthesis. May involve a meta-analysis
What is a meta analysis?
Quantitative synthesis of two or more primary studies that addressed the same hypothesis in the same way
