Statistica Flashcards
Bot plot
Box always shows the median and the two quartiles (the 1st and the 3rd)
The whiskers of the box plot can represent different values depending on the specific box plot.
Use of box plot
comparing data between many sets of data, such as many different populations.
Pre-clinical.
Animal/cell testing to gather information about efficacy and toxicity.
Phase 0
small group of volunteers, used to assess pharmacodynamics and pharmacokinetics
Phase 1
Testing of drug on healthy volunteers to find appropriate dosing
Phase 2
Testing of drug on large group of patients to assess efficacy and safety
phase 3
Testing of drug on a large group of patients to confirm effectiveness, safety and comparing to existing interventions
Confidence intervals
range within which the true treatment effect is likely to lie.
Sensitivity
proportion of people with the condition who will have a positive result
Sensitivity = a/(a+c)
Specificity
Specificity
Specificity describes the proportion of people without the disease who will have a negative test.
Specificity = d/(b+d)
Positive predictive value (PPV)
proportion of people with a positive test who actually have the disease.
PPV varies with prevalence of disease in a population.
The lower the prevalence, the lower the positive predictive value.
PPV = a/(a+b)
Negative predictive value
proportion of people with a negative test who truly do not have the disease.
NPV = d/(c+d)
False positive rate
The false positive rate is the proportion of those without the condition who will test positive.
False positive rate = 1 - specificity
False negative rate = 1 - d/(b+d)
False negative rate
The false negative rate is the proportion of those with the condition who will test negative.
False negative rate = 1 - sensitivity
False negative rate = 1 - a/(a+c)