Epi cards Flashcards
What infections are on the rise?
Tuberculosis
Dengue Fever
What infections is there a decline in?
Stomach cancer and lung cancer
what is likelihood of cancer in less developed countries?
60%
what are the Most common diagnosed cancers?
Lung
Breast
Colorectal
What are the most causes of cancer death?
Lung
Liver
Stomach
How long does it take for cancer to appear?
20 years
What are the major carcinogens?
- Tobacco
- alcohol
- air pollution
- occupational agents
What study can we measure prevalence from?
cross sectional studies.
Prevalence is a proportion.
What are the leading causes of death
heart diseases, cerebro-vascular disease, respiratory infections, HIV/AIDS, COPD
what are the infectious disease that causes most of the death (90%)?
lower respiratory infections, HIV/AIDS, diarrhoeal diseases, tuberculosis, malaria and measles.
what percentage and what type of cardiovascular disease leads to death?
- Mainly coronary heart disease and stroke.
- 29.5%
what 3 factors related to diet and lifestyle is particularly important?
- Blood pressure
- tobacco smoking
- serum cholesterol levels
What is the fold growth of access to therapy for HIV/AIDS
10 fold
what does SMR take into account and what is it?
Used for comparing one area with a “standard population”, adjusting for age (often also sex)
Represents the ratio of the number of observed deaths (or cases of disease) (O) in a particular population to the number that would be expected (E), if that population had the same mortality or morbidity experience as a standard population, corrected for differences in age (and sex) structure.
Taking into account for the effect of age
It is a ratio.
At the end of a trial, what calculations can be done when presenting the findings?
The experimental event rate (EER) = incidence in the intervention arm
Control event rate (CER) = incidence in the control arm
Relative risk = EER/CER
Relative reduction = (CER- EER)/ CER
Absolute risk reduction (ARR) = CER- EER
Number needed to treat (NNT) = 1/ARR
What is incidence?
Overall incidence = new cases in cohort/total number in cohort
What is the relative risk?
The relative risk is the incidence in the exposed group (non-circumcised) divided by the incidence in the non-exposed group (circumcised)
what is attributable risk (or attributable fraction)
The risk difference
Attributable Risk = Incidence in the Exposed – Incidence in the Unexposed.
How to work out odds and when do you work out odds?
For case-control
Odds of exposure in the disease/ odds of exposure in the disease free- free group control)
What is the mathematical relationship between odds and probability?
probability / (1 – probability)
advantages of a systematic approach
Transparent process because of the explicit methods in identifying and rejecting studies.
A meta-analysis, if appropriate, will increase the power of the study and enhance the precision of estimates of treatment effects, accounting for sample size, and uncertainties.
Systematic reviews may demonstrate the lack of adequate evidence and thus identify areas where further studies are needed.
What is involved in a systematic review?
Stage I Planning the review Stage II Identification of research Stage III Reporting and dissemination
Meta-analysis: strengths and limitations
More subjects can be included than any single constituent study, producing a more reliable and precise estimate of effect;
Differences (heterogeneity) between published studies can be identified and explored.
If the studies are too heterogeneous, it may be inappropriate, even misleading to statistically pool the results from separate studies.
how can heterogenity be explored?
Galbraith (radial) plots.
if too much heterogeneity exists, it might not be appropriate to pool the studies.
what are Receiver Operator Characteristics (ROC) curves used for
Receiver Operator Characteristics (ROC) curves are used to determine a cut-off value for a diagnostic or screening test.
What type of test would you do for accuracy of diagnostic test?
Cross-sectional design
What type of study for prognosis of disease?
Cohort study
What type of study when you want to work out causes and risk factors of disease: ?
various non-randomised design
study for population healthcare needs?
Various including ecological studies
What to do for treatment efficacy?
Randomised trial
how often does the census happen in the UK?
every 10 years
which type of study is good for studying rare diseases?
Case-control studies
NOT rare exposure
How to carry out a case-control study?
- Select cases with disease and controls without disease
- Obtain information on past exposures and other factors
- compare proportions of people exposed in cases and controls
advantages of Cohort studies?
Can look at multiple outcomes
Can follow through the natural course of the disease
Can calculate incidence
Good to look at rare exposures
What is an advantage of case-control studies?
Can examine effects of multiple exposures.
