Self-tests Flashcards
Type 1 diabetes is not influenced more by genetic factors than type 2 diabetes.
True/false?
True
What happens to the incidence figures when introducing a large-scale screening programme?
the incidence figures of that disease often go up dramatically.
Attack rates are mainly used in the field of..
infectious disease
A survival curve shows..
the proportion of a population living after a given age or getting a disease.
The Life Expectancy is expressed for 1 person, and the Years of Life Lost for the whole population.
ok biatch
Health Gap’ means?
that there is a difference between a current situation and an ideal situation where everyone in the population lives up to the age of the standard life expectancy in perfect health.
Are cohort studies always done in populations that are free of the disease of interest at baseline?
Cohort studies are not always done in populations that are free of the disease of interest at baseline. Prognostic cohort studies mainly focus on diseased populations.
In a historical cohort study, assessment of the exposure takes place after assessment of the outcome. True/false?
False. It makes use of exposure data that have already been collected in the past.
What is the ‘treatment effect’ in an RCT?
the change in outcome in the intervention group minus the change in the control group.
What do you randomize in a cross-over trial?
treatment order, not subjects
In a community trial, randomisation takes place on the … level.
group
In a parallel trial, you need more/less people than in a crossover trial to have the same statistical power
more, In a crossover trial the response of a subject to treatment A is contrasted with the same subject’s response to treatment B. Removing patient variation in this way makes crossover trials more efficient than similar sized, parallel group trials in which each subject is exposed to only one treatment.
What is the risk ratio?
= Ipe/IP0
Odds ratio can range from..
range from almost 0 to infinity
For a given disease, the sum of population attributable risks for different risk factors can exceed 100%, because..
multiple causes interact to cause disease
The proportion of disease in exposed people that can be attributed to the exposure is called
the attributable fraction
PAR = AR x ?
multiplied by the prevalence of the exposure in the population
Selection bias cannot be reduced by increasing the size of the study sample, because..
Bias has to do with validity, not with precision.
PAR = sensitive/not sensitive to bias
sensitive
Ascertainmant bias example?
investigator more often sending people with yellow fingers to hospital for lung cancer than persons without yellow fingers
What is the healthy worker effect?
a type of selection bias, when less healthy workers are more likely to reduce their workplace exposures
Loss to follow-up in a cohort study or clinical trial does not necessarily lead to biased results, except when..
more people are ‘lost to follow-up’ in one exposure group than another and if loss is also related to the outcome of interest.
Bias ‘from the null’ means..
that the bias is likely to have made the association appear stronger
Attrition bias may result from ?
loss to follow-up in a cohort study or clinical trial.
Cases and controls are selected dependently/independently of exposure status
independently, to avoid bias
True/false: there is confounding in trials with a large sample size
False: randomization results in equally balanced characteristics in the intervention and control group. In a small trial, however, you can have ‘bad luck’ with randomisation, and differences in baseline characteristics between the intervention and control group may be present.
Does a sufficient cause inevitably cause disease?
Yes
When a risk factor is causal, does it necessarily contribute to the disease occurrence in all exposed persons?
No, A component cause does not always have to be a necessary cause, and diseases may be caused by different sets of component causes in different individuals.
NPV = ? formula
true negatives/ tested negative
Attack rate is in …
%
What is the measure of association in an ecological study?
association/correlation
Poor diet + lifestyle is how many % of CVD burden?
> 75%
PAR = determined by association of exp-outcome and no of person with exp
ok
What is a valid study design for association of genetic factors + chronic disease?
Cross-sectional
