Exam 2 Flashcards
(32 cards)
Researcher conducting the statistical analysis that has not had any contact with the individuals whose data are being examined
Secondary analysis
Information previously gathered for a different purpose that may be relevant to the problem at hand
Secondary data
What are the advantages of secondary data?
low cost and effort, more timely, some info is only from secondary data sources
What are the limitations of secondary data?
Lack of availability, relevance, inaccuracy
How do retrospective and prospective cohort studies recruit participants based on?
Exposure status
Use baseline information collected at some point in the past and follow the cohort to another point in the past or present
Retrospective cohort study
Collect baseline data about the exposures and outcomes in the present and follow the cohort to some point in the future
Prospective cohort study
What is the goal of cohort studies?
examine incident disease
Recruit participants based on their membership in a well defined source population, then follow them forward in time
Longitudinal studies
All participants start the study at the same time and no one is allowed to join later
Fixed population
Participants recruited using rolling admission and replacement of dropouts
Dynamic population
Number of new cases of disease in a population
incidence rate
how do you find incidence rate? (IR)
number of new cases/ total number of persons in the population at risk
way of accounting for different individuals in the study population being observed for different lengths of time
person time
How do you find attributable risk? (AR)
absolute incidence rate minus unexposed population
How do you find AR%
incident cases/ exposed
How do you find rate ratio (RR)
Ratio of incidence rate among the exposed to incidence rate in the unexposed
Participants with the disease of interest
Case
Participants without the disease
Control
When is a case control study the best study?
When the disease is uncommon
Should specify exactly what characteristics must be present or absent for a person to be deemed a case
Case definition
What are the limitations to matching?
Variables used as matching criteria cannot be considered as exposures during analysis, can be difficult to find controls who meet all matching criteria
type of bias where cases and controls systematically have different memories of the past
Recall bias
How do you find odds ratio (OR)
ratio of the odds of exposure in cases to the odds of exposure in control
