Exam 2 Flashcards
Descriptive analysis
“to describe burden of disease or prevalence
of risk factors, health behaviors, or other characteristics
of a population that influences risk of disease” (CDC,
2015b).
Analytical Analysis
usually concerned with
identifying or measuring the effects of risk
factors or is concerned with the health effects
of specific exposure(s)” (Last, 2001).
answers questions about why and how
Clinical Trials
A research activity that involves the
administration of a test regimen to humans to
evaluate its efficacy and safety
What are the characteristics of a Clinical trial?
Carefully designed and rigidly enforced
protocol
* Tightly controlled in terms of eligibility, delivery
of the intervention, and monitoring out
outcomes
* Duration ranges from days to years
* Participation is generally restricted to a highly
selected group of individuals.
What are the outcomes of a Clinical Trial?
-Referred to as clinical end points
*May include rates of disease, death, or
recovery
*The outcome of interest is measured in the
intervention and control arms of the trial to
evaluate efficacy–these must be
measured in a comparable manner.
Blinding
Helps to maintain the integrity of the study and reduce the potential of bias. Single and double.
Cross sectional study
A research design that collects data from many different individuals at a single point in time. This allows you to measure the cause and the effect of the disease at the same point in time. You can simultaneously collect information on both the exposures and the outcomes.
Controls/ Exposures
A sample of the source population that produced the cases
Disease/ Cases
must be clearly defined. A person that has the disease.
Retrospective study
Looks back in time to examine health events that have occurred.
Prospective
Looks forward and examines future health outcomes
Cohort study
-Allows a researcher to investigate the association between an exposure and an outcome or disease.
Allow for incidence to be determined
* Contribute to our understanding of cause and effect
* Collects primary data (i.e., data that the researcher collects him/herself)
Can calculate risk difference and risk ratio
Case-Control
Usually used to study rare diseases or multiple exposures that could be related to a single outcome.
Compares the frequency of exposure among cases vs. controls. cannot estimate disease rates.
matching
The process of making a study group and a comparison group comparable with respect to extraneous factors.
purpose of epi studies?
experimental vs observational
An experimental study (Clinical trails, randomized trials) has a research question involving prevention and treatment, feasible, money is available and a small effect is expected.
Observational (Cohort, case-control, cross-sectional) involves a question of prevention and treatment or a causal factor. Trial of it is not ethical, is infeasible, and would be too expensive.
what is blinding in a clinical trial?
A way to protect the integrity of the study by preventing bias of who is receiving what treatment
What is a disadvantage of a clinical trial?
It is an artificial setting, limited scope of potential impact, adhering to the protocols can be difficult, ethical dilemmas, expensive.
Strengths and weaknesses of a cohort study?
Very time consuming to follow all the people, you need to be able to follow them for a long period of time, expensive, not good for rare diseases, or diseases with long latency periods. Loss to follow up can potentially decrease the validity.
strengths:
Clear temporal sequence, efficient for rare exposures, good information on exposures, confounders, especially, can study effects of exposure on multiple outcomes.
strength and weaknesses of an experimental study?
not always ethical, can be expensive, lots of complicated protocols. You can determine causation.
strength and weakness of a case control study?
Good for studying really rare diseases and can measure exposure related to multiple risks.
Weakness: we pick the population so there is no total population. Retrospective direction of inquiry.
Cumulative incidence or risk
Can be calculated for Cohort Studies and case-control studies.
= # with the disease/ total population at risk
Risk Ratio
=Cumulative incidence(exp)/ Cumulative incidence (unexp)
