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Stack #2728794

Types of observational studies (5) Cross-sectional , case control, cohort , twin concordance and adoption.
Collects data from a group of people to asses frequency of disease at a particular point in time ( disease prevalence Cross-sectional study
Compares a group of people with disease to a group without disease (odds -ratio) Case-control study
Compares a group with a given exposure or risk factor to a group without such exposure (relative risk) Cohort study
Compares the frequency with which both monozygotic twins or dizygotic twins develop the same disease ( measures heritability and influence of environmental factors Twin concordance study
Compares siblings raised by biological vs adoptive parents Adoption study
Experimental study involving humans. Compares therapeutic benefits of 2 or more treatments, or of treatment and placebo Clinical trial
The sample consists on a small number of healthy volunteers (is it safe?) Phase 1 drug trials
The sample consists on a small number of patients with disease of interest ( does it work) Phase 2 drug trial
The study sample consists on a large number of patients randomly assigned either to the treatment under investigation or to the best available treatment ( or placebo)( is it as good or better?) Phase 3 drug trials
Is the post marketing surveillance of patients after treatment is approved Phase 4 drug trial
Proportion of all people with disease who test positive, or the probability that when the disease is present , the test is positive Sensitivity ( true positive rate )
Sensitivity formula SENS = TP/ ( TP + FN)
Proportion of all people without disease who test negative, or the probability that when the disease is absent, the test is negative Specificity ( true negative rate )
Specificity formula SPECIFICITY = TN / (TN +FP)
Proportion of positive test results that are true positive Positive predictive value
Positive predictive value formula PPV = TP / ( TP + FP)
Proportion of negative test results that are true negative Negative predictive value
Negative predictive value formula NPV = TN / ( TN + FN)
Created by: mune13