Heath and Society - Statistics Flashcards
Disadvantages of cohort studies
Expensive
attrition (i.e. people may drop out)
Must consider how long for risk factor to cause disease
Disadvantages for case control
Recall bias
Advantages of case control study
observational study
good for rare diseases
Good for tracing source of an outbreak
What should be considered when critiquing systematic reviews
Inclusion of studies:
Publication bias
Studies not in english
Define sensitivity
the likelihood that a test will pick up someone with disease
A highly specific test will…
Correctly identify a high proportion of people free from disease
A D dimer test is highly specific therefore it has a low or high number of false negatives
low false negative
Define positive predictive valve
Probability that those with a positive result truly have disease
Define negative predictive value
probability that those with a negative result truly are disease free
What is a 95% confidence value
The range in which the population mean is 95% likely to lie
What is a p value
Probability of results being found if there is no difference in treatments (accept null hypothesis)
Risk ratio
Ratio of the risk of an event between two groups
used in cohort studies
Odds ratio
chance that something will happen : compared to chance that something will not
(used in case control studies)
Define relative risk
One population’s risk compared to another population
Define absolute risk
one population’s risk in its own right
