22 Questions
A ______ study examines a point in time and measures prevalence, not incidence of disease.
cross-sectional
Cannot adjust for confounds due to lack of ______ (due to lack of data on all potential covariates).
comparability
A ______ study compares exposures in disease cases versus healthy controls from the same population.
case-control
The main disadvantage of cross-sectional studies is that they measure ______, not incidence of disease.
prevalence
Cross-sectional studies are suitable for studying conditions that are relatively frequent with ______ duration of expression.
long
Cross-sectional studies allow for the study of ______ diseases/exposures.
several
One of the advantages of cross-sectional studies is that they are ______ in terms of cost and time.
low
The ______ sequence of exposure and effect is difficult to determine in cross-sectional studies.
temporal
Cohort studies allow for the ability to study several ______ for each exposure.
outcomes
A major disadvantage of cohort studies is that they are ______.
expensive
Randomized Controlled Trials (RCTs) are considered the ______ standard for epidemiological research.
gold
The primary purpose of randomization in RCTs is to reduce ______ bias in the allocation of intervention.
selection
Randomization helps to control for ______ and unknown factors in RCTs.
known
Cohort studies are not suitable for ______ diseases or diseases with long latency.
rare
A major limitation of cohort studies is the potential for ______ to follow-up.
loss
Blinding of participants and researchers in RCTs reduces ______ in assessment of outcomes.
bias
In a case-control study, exposure data is collected ______ and the outcome of disease is already known.
retrospectively
A major advantage of case-control studies is that they are ______ compared to other designs.
less time-consuming
Case-control studies are most feasible for disease outcomes that are ______.
rare
Cohort studies follow a condition or disease into the ______ to determine which risk factors are associated with it.
future
In a case-control study, the selection of study subjects can be influenced by ______ status.
disease
A disadvantage of case-control studies is that they are not suitable when the disease outcome for a specific ______ is not known at the start of the study.
exposure
Study Notes
Study Design Issues
- Cannot adjust for confounds due to lack of comparability in cross-sectional studies
- Missing data is a limitation in studies
Cross-Sectional Study
- Surveys exposures and disease status at a single point in time
- Measures prevalence, not incidence of disease
- Suitable for studying nonfatal, chronic conditions
- Not suitable for studying rare or highly fatal diseases
- Advantages: low cost, convenient, less time-consuming, allows study of several diseases/exposures
- Disadvantages: weaker design, difficult to determine temporal sequence of exposure and effect, prevalence is measured, not incidence
Case-Control Study
- Compares exposures in disease cases versus healthy controls from the same population
- Exposure data is collected retrospectively
- Advantages: low cost, less time-consuming, most feasible design for rare disease outcomes
- Disadvantages: not suitable when disease outcome for a specific exposure is not known, exposure measurements are taken after disease occurrence, disease status can influence selection of study subjects
Cohort Study
- One or more cohorts are followed prospectively
- Ability to study several outcomes for each exposure
- Disadvantages: expensive, time-consuming, not suitable for rare diseases or diseases with long latency, no randomization, loss to follow-up
Randomized Controlled Trials (RCTs)
- Experimental comparison study where participants are randomized to experimental or control groups
- Best for studying the effect of a treatment/test
- Gold standard for epidemiological research
- Primary purpose of randomization: reduces selection bias in intervention allocation
- Secondary purpose: ensures similar baseline characteristics in experimental and control groups
- Advantages: randomization balances distribution of confounders, blinding reduces bias, detailed information collected at baseline and follow-up
This quiz covers the concepts of cross-sectional study, epidemiology, and data analysis, including limitations and challenges.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
