3: Epidemiology and Public Health in Dermatology Flashcards
1
Q
What is the definition of epidemiology in the context of public health?
A
Epidemiology is the study of disease in a population, which includes the incidence, prevalence, distribution, cause, and natural history of disease.
2
Q
What are clinical trials and their significance in epidemiology?
A
Clinical trials are interventional studies that include randomized controlled trials (RCTs). They provide the highest level of proof of an effect by minimizing bias (internal validity), although they may not generalize well to all members of a population (external validity).
3
Q
What is the role of health services research in public health?
A
Health services research evaluates how individuals receive health care and interact with the health care system, including evaluations of access to care, interactions between health care providers and patients, and a patient’s perception of their illness.
4
Q
What does patient-oriented research focus on?
A
Patient-oriented research focuses on studies of how patients interact with their health care and disease, with outcomes often directed by or informed by individuals with an illness of interest.
5
Q
What is meant by the ‘burden of disease’?
A
The burden of disease is a measure of how an individual is affected by an illness, which can include various outcomes such as death, onset, resolution, or change in the status of an illness.
6
Q
What are the key criteria for establishing a causal association in epidemiology?
A
Key criteria for establishing a causal association include: 1) a risk factor must occur before the outcome, 2) the risk factor should not be part of another factor’s causal pathway, 3) prior knowledge of the risk factor should provide evidence that it could cause the outcome, 4) there should be a strong and dose-dependent association between the risk factor and outcome, and 5) the association must be reproducible.
7
Q
What is the difference between bias and confounding in epidemiological studies?
A
Bias refers to systematic errors that cause the results of a study to deviate from the truth, such as selection bias and information bias. Confounding occurs when two risk factors or exposures are associated with each other and the outcome of interest, often distorting the estimated effect of either risk factor on the outcome.
8
Q
How is efficacy defined in the context of clinical studies?
A
Efficacy is defined as a measure of an effect in an ideal setting, characterized by maximized internal validity and minimized potential errors or confounding.
9
Q
A clinical trial is conducted to test a new drug for psoriasis. The trial is tightly controlled and aims to minimize bias. What type of validity is being maximized, and why might the results not generalize to the entire population?
A
The trial is maximizing internal validity by minimizing bias. However, the results might not generalize to the entire population due to limited external validity, as the controlled environment may not reflect real-world conditions.
10
Q
You are designing a study to evaluate how patients perceive their illness and interact with healthcare providers. What type of research is this, and what outcomes might it focus on?
A
This is patient-oriented research, which focuses on outcomes such as patient perceptions, interactions with healthcare providers, and the overall experience of managing their illness.
11
Q
A study finds a strong, dose-dependent association between a risk factor and an outcome. What criteria are being met to establish a causal association?
A
The criteria being met include a strong and dose-dependent association, reproducibility, and a biologically plausible explanation for the relationship between the risk factor and the outcome.
12
Q
In a study, researchers observe that individuals with a specific risk factor are more likely to develop a disease. What measure is used to quantify this association, and how is its significance determined?
A
The measure used is an effect estimate, such as a risk ratio or odds ratio. Its significance is determined by statistical significance tests.
13
Q
A study is criticized for having selection bias. What is selection bias, and how might it affect the study’s results?
A
Selection bias is a systematic error caused by how subjects are selected or not selected for a study. It can distort the study’s results by making them unrepresentative of the target population.
14
Q
A study is designed to evaluate the natural history of a rare skin disease. What outcomes might this study focus on?
A
The study might focus on the disease’s onset, progression, resolution, or the patient’s end.
15
Q
A study evaluates the burden of a chronic skin condition. What factors might be included in this measure?
A
Factors might include the physical, emotional, and social impact of the condition on the individual’s quality of life.
16
Q
A study is criticized for confounding. What is confounding, and how can it affect study results?
A
Confounding occurs when two risk factors are associated with each other and the outcome, distorting the estimated effect of either risk factor on the outcome.
17
Q
A study finds that a risk factor occurs before the outcome and is not part of another factor’s causal pathway. What criteria for causality does this fulfill?
A
This fulfills the criteria of temporality and independence in establishing a causal association.
18
Q
What are the key characteristics of clinical trials?
A
Clinical trials are interventional studies that include randomized controlled trials (RCTs), where the investigator has a direct influence on subjects via an intervention, and the experimental environment is tightly controlled to determine the efficacy of the intervention.
19
Q
What is the purpose of health services research?
A
Health services research evaluates how individuals receive health care and interact with the health care system, including access to care, interactions between health care providers and patients, and patients’ perceptions of their illness.
20
Q
How does patient-oriented research differ from other types of research?
A
Patient-oriented research focuses on studies of how patients interact with their health care and disease, often directed by or informed by individuals with an illness of interest.
21
Q
What does the natural history of disease refer to?
A
The natural history of disease refers to the course of the disease from its onset until its resolution, which may be a study outcome of interest.
22
Q
What is a causal association in epidemiology?
A
A causal association is the strongest link between a risk factor or intervention and an outcome, established through a clear temporal relationship, explicit definition of the outcome, and biological plausibility.
23
Q
What are the criteria established by Sir Bradford Hill for determining causal associations?
A
Sir Bradford Hill’s criteria include: 1) A risk factor must occur before the outcome; 2) The risk factor should not be part of another factor’s causal pathway; 3) Prior knowledge of the risk factor should provide evidence of its potential to cause the outcome; 4) There should be a strong and dose-dependent association between the risk factor and outcome; 5) The association must be reproducible.
24
Q
What is the role of bias in epidemiological studies?
A
Bias is a systematic error that causes the results of a study to deviate from the truth, affecting the validity of the study’s conclusions.
25
What is confounding in the context of epidemiological research?
Confounding occurs when two risk factors or exposures are associated with each other and the outcome of interest, often distorting the estimated effect of either risk factor on the outcome.
26
How is efficacy defined in clinical research?
Efficacy is defined as the measure of an effect in an ideal setting, characterized by maximized internal validity and minimized potential errors or confounding.
27
What is the significance of statistical significance in epidemiological studies?
Statistical significance indicates the likelihood that an observed association is real and not due to chance, often measured by an effect estimate.
28
What are the two main types of bias that can affect study results?
The two main types of bias are: 1) Selection bias, which occurs due to how subjects are selected for a study; 2) Information bias, which arises from inaccuracies in reporting data.
29
What is the difference between internal validity and external validity in clinical trials?
Internal validity refers to the degree to which the results of a study are attributable to the intervention itself, while external validity refers to the extent to which the study's findings can be generalized to a broader population.
30
What is the primary observation of interest in epidemiological studies?
The primary observation of interest in epidemiological studies is the outcome, which may include death, the onset, resolution, or change in the status of an illness, and quality of life.
31
What is the role of interventions in epidemiological studies?
Interventions are applications of a substance or action to subjects in an experimental study, aimed at determining the effect of the intervention on health outcomes.
32
How can the effectiveness of an intervention be assessed in clinical trials?
The effectiveness of an intervention can be assessed by comparing outcomes between groups receiving the intervention and those not receiving it, while controlling for potential biases and confounding factors.
33
What is the importance of defining outcomes before a study commences?
Defining outcomes before a study commences is crucial for ensuring clinical relevance and clarity in measuring the effects of interventions or exposures.
34
What is the significance of a clear temporal relationship in establishing causal associations?
A clear temporal relationship is significant because it demonstrates that the risk factor or intervention precedes the outcome, which is essential for establishing causality.
35
What does it mean for a study to be internally valid?
A study is considered internally valid when it accurately measures the effect of the intervention without being influenced by biases or confounding factors.
36
What is the impact of selection bias on study results?
Selection bias can lead to systematic differences between groups in a study, potentially skewing results and leading to incorrect conclusions about the effectiveness of an intervention.
37
How does patient perception influence health services research?
Patient perception influences health services research by providing insights into how individuals experience care, which can inform improvements in health care delivery and policy.
38
What is the relationship between risk factors and disease outcomes?
Risk factors are attributes that increase the likelihood of developing a disease or other outcomes, and understanding this relationship is crucial for prevention and intervention strategies.
39
What is the role of effect estimates in epidemiological studies?
Effect estimates quantify the strength of the association between a risk factor and an outcome, helping to determine the clinical significance of findings.
40
What are the implications of confounding in interpreting study results?
Confounding can obscure the true relationship between risk factors and outcomes, making it difficult to determine the actual effect of an intervention or exposure.
41
What is the significance of biological plausibility in establishing causal associations?
Biological plausibility supports the likelihood that a causal relationship exists by providing a scientifically reasonable explanation for how a risk factor could lead to an outcome.
42
How can researchers minimize bias in clinical trials?
Researchers can minimize bias in clinical trials by using randomization, blinding, and standardized protocols to ensure that the study conditions are as controlled as possible.
43
What is the importance of understanding the natural history of a disease in epidemiology?
Understanding the natural history of a disease helps researchers identify critical points for intervention and informs the development of effective prevention and treatment strategies.
44
What factors contribute to the burden of disease in a population?
Factors contributing to the burden of disease include the prevalence of illnesses, their severity, the impact on quality of life, and the economic costs associated with treatment and care.
45
What is the role of statistical significance in determining the validity of study findings?
Statistical significance helps determine whether the observed effects in a study are likely due to the intervention rather than random chance, thus supporting the validity of the findings.
46
How does the concept of risk factor association inform public health interventions?
Understanding risk factor associations informs public health interventions by identifying target areas for prevention efforts, ultimately aiming to reduce disease incidence and improve health outcomes.
47
What is the significance of the outcome in epidemiological studies?
The outcome is significant as it represents the primary measure of interest in a study, reflecting the effectiveness of interventions and the impact of risk factors on health.
48
What are the potential consequences of information bias in research studies?
Information bias can lead to inaccurate data collection and reporting, ultimately distorting the study's findings and undermining the reliability of conclusions drawn from the research.
49
How can understanding the burden of disease influence health policy decisions?
Understanding the burden of disease can guide health policy decisions by highlighting areas of need, allocating resources effectively, and prioritizing interventions that address significant health issues.
50
What is the relationship between health services research and patient outcomes?
Health services research examines how care delivery affects patient outcomes, aiming to improve the quality, efficiency, and accessibility of health care services.
51
What are the key differences between explanatory studies and pragmatic studies in clinical research?
**Explanatory Studies**:
- Measure efficacy in ideal conditions.
- Often lack real-world applicability.
- Focus on internal validity.
**Pragmatic Studies**:
- Measure effectiveness in real-world settings.
- Allow for imprecisions and variability in treatment.
- Aim to maximize generalizability and minimize regulatory burdens.
52
What are the phases of clinical trials and their primary objectives?
| Phase | Objective |
|-------|-----------|
| Phase I | Assess safety, tolerability, and pharmacokinetics in humans. |
| Phase II | Determine initial efficacy and gather additional information for Phase III. |
| Phase III | Compare efficacy against a control treatment; provide data for regulatory approval. |
| Phase IV | Evaluate long-term effectiveness and safety post-marketing. |
53
What is the significance of randomization and blinding in Phase III studies?
Randomization and blinding are crucial in Phase III studies to:
- Ensure **internal validity** by minimizing bias.
- Provide a fair comparison between the treatment and control groups.
- Enhance the reliability of the results for regulatory agencies like the FDA.
54
What is the role of pragmatic trials in clinical research?
Pragmatic trials aim to:
- Assess how interventions work in routine clinical settings.
- Maximize the **generalizability** of results across various practice environments.
- Minimize scientific, regulatory, and administrative burdens common to explanatory trials.
55
What are the two basic categories of study designs in epidemiology?
The two basic categories of study designs in epidemiology are:
1. **Analytic Studies**: Examine associations between exposures and outcomes.
2. **Descriptive Studies**: Describe characteristics of a population or phenomenon without focusing on cause-and-effect relationships.
56
A new drug is tested in a Phase III clinical trial. What is the primary goal of this phase, and what design elements are crucial for its success?
The primary goal of a Phase III trial is to assess the efficacy of the drug compared to a control treatment. Crucial design elements include randomization and blinding to ensure internal validity and reduce bias.
57
A study compares two treatments for eczema in a real-world setting without strict regulatory oversight. What type of study is this, and what is its primary focus?
This is a comparative effectiveness study, often called a pragmatic study. Its primary focus is on how well the treatments work in routine clinical settings.
58
A Phase IV study is conducted after a drug is approved. What are the primary objectives of this phase?
The primary objectives are to assess the drug's effectiveness in the general population, monitor long-term safety, and evaluate its use for indications other than those approved.
59
A study aims to maximize generalizability while minimizing regulatory and scientific burdens. What type of trial is this, and what is its primary goal?
This is a pragmatic trial, and its primary goal is to understand how an intervention works in routine clinical settings.
60
A study evaluates the effectiveness of a new treatment in a real-world setting. What type of validity is being prioritized, and why?
External validity is being prioritized to ensure the results are generalizable to the broader population.
61
A study uses the PRECIS tool to classify its design. What is the purpose of this tool, and in what type of study is it used?
The PRECIS tool is used to classify studies along the pragmatic-explanatory continuum, helping to determine how closely the study design aligns with real-world settings.
62
A study evaluates the effect of a new drug in a Phase II trial. What is the primary focus of this phase?
The primary focus of a Phase II trial is to determine initial efficacy and gather additional information for Phase III.
63
What type of validity is being prioritized, and why?
External validity is being prioritized to ensure the results are generalizable to the broader population.
64
What is the purpose of the PRECIS tool, and in what type of study is it used?
The PRECIS tool is used to classify studies along the pragmatic-explanatory continuum, helping to determine how closely the study design aligns with real-world settings.
65
What is the primary focus of a Phase II trial?
The primary focus is to determine the initial efficacy of the drug and gather information to design Phase III trials.
66
What is the difference between explanatory studies and pragmatic studies in clinical research?
**Explanatory studies** focus on measuring efficacy under ideal conditions, while **pragmatic studies** assess effectiveness in real-world settings, allowing for variability in treatment and patient interactions.
67
What are the key phases of clinical trials and their primary objectives?
| Phase | Objective |
|-------|-----------|
| Phase I | Assess safety, tolerability, and pharmacokinetics in humans. |
| Phase II | Determine initial efficacy and gather data for Phase III design. |
| Phase III | Compare efficacy against a control and provide data for regulatory approval. |
| Phase IV | Evaluate long-term effectiveness and safety post-marketing. |
68
How do Phase III studies contribute to the regulatory approval process of new treatments?
Phase III studies, also known as comparative efficacy studies, provide essential data to regulatory agencies like the FDA to determine whether to approve a new drug based on its efficacy compared to a control treatment.
69
What is the significance of randomization and blinding in clinical trials?
Randomization and blinding are crucial for ensuring **internal validity** and reducing **bias**, which enhances the reliability of the trial results and the conclusions drawn about the treatment's efficacy.
70
What are pragmatic trials and how do they differ from traditional clinical trials?
Pragmatic trials, also known as large simple studies, focus on understanding how an intervention works in routine clinical settings, aiming to maximize generalizability and minimize regulatory and administrative burdens compared to traditional clinical trials.
71
What is the role of the FDA in the classification of clinical trials?
The FDA classifies clinical trials based on their design and purpose, providing guidance on the phases of trials, which include Phase I for safety, Phase II for efficacy, Phase III for comparative effectiveness, and Phase IV for post-marketing evaluation.
72
What are the characteristics of cohort studies in epidemiology?
Cohort studies involve a group of people defined by a specific characteristic, such as disease status or risk factor, and are used to observe outcomes over time, often in observational research settings.
73
What is the purpose of comparative effectiveness studies?
Comparative effectiveness studies aim to compare two or more treatments that are generally accepted to be effective, assessing their performance in real-world settings to inform clinical decision-making.
74
How do Phase IV studies differ from Phase III studies in terms of their focus?
Phase IV studies, conducted after FDA approval, focus on the long-term effectiveness and safety of a treatment in the general population, while Phase III studies primarily assess efficacy compared to a control group before approval.
75
What guidelines are used for quality reporting in randomized controlled trials (RCTs)?
The **Consolidated Standards of Reporting Trials (CONSORT)** statement provides guidelines for quality reporting in RCTs, ensuring transparency and completeness in the presentation of trial results.
76
What is the primary difference between efficacy and effectiveness research?
Efficacy research focuses on how an intervention works in ideal settings with stringent patient selection, while effectiveness research examines how the intervention works in real-world settings with heterogeneous patient populations.
77
What are the advantages and disadvantages of cohort studies?
Advantages:
- Ability to evaluate multiple outcomes in a single study.
- Can calculate incidence rates.
Disadvantages:
- Tend to be large and time-consuming.
- Subject to bias, especially if retrospective.
78
How does a case-control study differ from a cohort study?
A case-control study samples individuals with a disease (cases) and compares them to those without the disease (controls) to determine risk factors, while a cohort study follows a group over time to monitor outcomes based on exposures.
79
What is the purpose of meta-analysis in research?
Meta-analysis aims to combine results from multiple studies to create a pooled effect estimate of an outcome of interest, often providing more precise estimates than individual studies, but can lead to biased results if not conducted carefully.
80
What are the key components of quality reporting in systematic reviews?
Key components include:
- AMSTAR for assessing systematic reviews.
- PRISMA for reporting systematic reviews and meta-analyses.
- QUOROM for quality reporting of meta-analyses.
- CONSORT for clinical trials.
- STROBE for observational studies.
81
What is the GRADE scale used for in epidemiology?
The GRADE scale is used to grade the quality of evidence and strength of recommendations in clinical guidelines and research, helping to assess the reliability of findings.
82
Define prevalence and incidence in the context of epidemiology.
Prevalence is the frequency of a disease or outcome of interest over a specified time period, while incidence refers to the frequency of new cases of a disease among those at risk within a specified time period.
83
What are the advantages and limitations of a cohort study evaluating smoking and lung cancer?
Advantages include the ability to evaluate multiple outcomes and calculate incidence rates. Limitations include being time-consuming, large in scale, and subject to bias.
84
What are the key advantages of a case-control study investigating a rare disease?
Key advantages include the ability to study rare outcomes and evaluate multiple risk factors quickly. Researchers should be cautious of selection and recall biases.
85
What is the primary benefit of a meta-analysis, and what potential issue should be considered?
The primary benefit is increased precision of the effect estimate. A potential issue is the introduction of bias if the combined studies are not comparable.
86
What does the GRADE scale assess, and why is it important?
The GRADE scale assesses the quality of evidence and the strength of recommendations. It is important for ensuring that clinical decisions are based on reliable and robust evidence.
87
What is the primary limitation of a cross-sectional study measuring psoriasis prevalence?
The primary limitation is that it cannot establish a temporal relationship between risk factors and outcomes.
88
What does an incidence measure of 5 cases per 1,000 individuals per year represent?
This measure represents the frequency of new cases of the skin condition among the at-risk population within a specified time period.
89
What type of prevalence is being measured in a study of eczema in children over a 12-month period?
The study is measuring yearly prevalence, which indicates the proportion of children who had eczema during the 12-month period.
90
What type of study uses CONSORT guidelines for reporting, and why are these guidelines important?
This is a clinical trial, and the CONSORT guidelines are important for ensuring transparent and standardized reporting of trial methods and results.
91
What is the key difference between incidence and prevalence?
Incidence measures the frequency of new cases in a population at risk over a specified time, while prevalence measures the total number of cases at a given time.
92
What type of study uses the AMSTAR tool for quality reporting, and what does the tool assess?
This is a systematic review or meta-analysis, and the AMSTAR tool assesses the methodological quality of the review.
93
What type of study uses the STROBE guidelines for reporting, and why are these guidelines important?
This is an observational study, and the STROBE guidelines are important for ensuring comprehensive and transparent reporting of study methods and findings.
94
What is the primary advantage of evaluating multiple outcomes in a cohort study?
The primary advantage is the ability to evaluate multiple outcomes and calculate incidence rates within the same cohort.
95
What is the unique advantage of a network meta-analysis?
The unique advantage is the ability to compare treatments that were not directly compared in individual studies.
96
What is the primary difference between efficacy and effectiveness research?
Efficacy research assesses how well an intervention works in ideal settings, focusing on stringent patient selection and internal validity. Effectiveness research evaluates how well the intervention works in real-world settings, considering heterogeneous patient populations and external validity.
97
What are the advantages and disadvantages of cohort studies in observational research?
Advantages:
1. Ability to evaluate multiple outcomes in a single study.
2. Can calculate incidence rates.
Disadvantages:
1. Tend to be large and time-consuming.
2. Subject to bias, especially if retrospective.
98
How does a case-control study differ from a cohort study?
A case-control study samples individuals with a disease (cases) and compares them to those without the disease (controls) to determine risk factors, while a cohort study follows a group over time to monitor outcomes based on exposures. Case-control studies are typically retrospective and quicker, while cohort studies are often prospective and more time-consuming.
99
What is the purpose of meta-analysis in research?
Meta-analysis aims to combine results from multiple studies to create a pooled effect estimate of an outcome of interest, enhancing the precision of estimates compared to individual studies. It can also facilitate comparisons between treatments that have not been directly compared in individual studies.
100
What are the key components of quality reporting in systematic reviews?
Key components include:
1. AMSTAR for assessing systematic reviews.
2. PRISMA for reporting systematic reviews and meta-analyses.
3. QUOROM for quality reporting of meta-analyses.
4. CONSORT for clinical trials.
5. STROBE for observational studies.
101
What is the GRADE scale used for in epidemiology?
The GRADE scale is used to grade the quality of evidence and strength of recommendations in clinical guidelines and systematic reviews, helping to assess the reliability of findings.
102
Define prevalence and its significance in epidemiology.
Prevalence is the frequency of a disease or other outcome of interest over a specified period of time, calculated as the number of individuals with the disease divided by the total number of individuals sampled. It is significant for understanding the burden of disease in a population.
103
What is the difference between point prevalence and yearly prevalence?
Point prevalence refers to the proportion of individuals who have a disease at a specific point in time, while yearly prevalence refers to the proportion of individuals who have had the disease at any time during a 12-month period.
104
What is the role of descriptive studies in epidemiology?
Descriptive studies report the distribution of disease or other health outcomes in a population, providing insights into patterns and trends that can inform further research and public health interventions.
105
What are the limitations of cross-sectional studies?
Cross-sectional studies provide a snapshot of a population at a single point in time, which limits their ability to establish causality or temporal relationships between exposures and outcomes. They are also subject to biases such as selection and recall bias.
106
What is the definition of effect estimate in epidemiology?
Effect estimate refers to the impact of a risk factor on an outcome of interest, typically measured as a **risk ratio**, **relative risk**, or **hazard ratio**. It compares how an outcome is measured in those with a disease versus those without a disease.
107
How is attributable risk defined in epidemiological studies?
Attributable risk, also known as risk difference, is defined as the **risk in exposed persons** minus the **absolute risk in nonexposed persons**.
108
What does the odds ratio represent in case-control studies?
The odds ratio represents the ratio of the odds that a case is exposed compared with the odds that a control is exposed. It is often calculated using **logistic regression**.
109
What are the two fixed characteristics used to evaluate diagnostic test performance?
The two fixed characteristics used to evaluate diagnostic test performance are **sensitivity** and **specificity**.
110
Define sensitivity in the context of diagnostic testing.
Sensitivity is the proportion of truly diseased individuals (true positives and false negatives) who are defined as having the disease by a test. It is also referred to as the **true positive rate**.
111
What is specificity in diagnostic tests?
Specificity is the proportion of individuals who truly do not have the disease (false positives and true negatives) and are defined by the test as not having the disease. It is also known as the **true negative rate**.
112
What is the positive predictive value in clinical testing?
The positive predictive value is the proportion of individuals who have a positive test that truly have the disease.
113
What does negative predictive value indicate in diagnostic testing?
Negative predictive value indicates the proportion of individuals who have a negative test and truly do not have the disease.
114
What are Patient Reported Outcome Measures (PROMs)?
Patient Reported Outcome Measures (PROMs) are tools that assess the experience of disease and health care directly from the patient’s self-report.
115
What does high sensitivity in a diagnostic test imply?
High sensitivity implies that the test is effective at identifying individuals who truly have the skin condition (true positives).
116
What does high specificity indicate about a diagnostic test?
High specificity indicates that the test is effective at correctly identifying individuals who do not have the disease (true negatives).
117
What does a positive predictive value of 90% mean in clinical terms?
It means that 90% of individuals who test positive for the disease truly have the disease.
118
What does an odds ratio of 2.5 indicate about a risk factor?
An odds ratio of 2.5 indicates that individuals with the risk factor are 2.5 times more likely to have the disease compared to those without the risk factor.
119
What is the significance of PROMs in clinical research?
PROMs are significant because they provide direct insights into the patient's experience of disease and healthcare, which can inform treatment decisions.
120
What does a risk difference of 10% indicate?
The risk difference indicates that the exposed group has a 10% higher absolute risk of the outcome compared to the non-exposed group.
121
In what type of study design is logistic regression most commonly used?
Logistic regression is most commonly used in case-control studies to calculate odds ratios.
122
What does a hazard ratio of 1.8 indicate about a treatment?
A hazard ratio of 1.8 indicates that the treatment is associated with an 80% higher risk of the outcome occurring compared to the control.
123
What does a negative predictive value of 95% mean in clinical terms?
It means that 95% of individuals who test negative for the disease truly do not have the disease.
124
What is the definition of effect estimate in the context of measures of association?
Effect estimate refers to the impact of a risk factor on an outcome of interest, typically expressed as a risk ratio, relative risk, or hazard ratio, comparing outcomes in those with a disease versus those without.
125
How is attributable risk or risk difference calculated?
Attributable risk or risk difference is calculated as the risk in the exposed persons minus the absolute risk in the nonexposed persons.
126
What does the odds ratio represent in case-control studies?
The odds ratio represents the ratio of the odds that a case is exposed compared with the odds that a control is exposed, and it may be calculated using logistic regression.
127
Define sensitivity in the context of diagnostic test performance.
Sensitivity is the proportion of truly diseased individuals (true positives and false negatives) who are correctly identified as having the disease by a test; it is also known as the true positive rate.
128
What is specificity in diagnostic testing?
Specificity is the proportion of individuals who truly do not have the disease (false positives and true negatives) and are defined by the test as not having the disease.
129
What is specificity in diagnostic testing?
Specificity is the proportion of individuals who truly do not have the disease (false positives and true negatives) and are correctly identified by the test as not having the disease; it is also known as the true negative rate.
130
Explain the concept of positive predictive value.
Positive predictive value is the proportion of individuals who have a positive test result that truly have the disease, indicating the test's effectiveness in identifying true cases.
131
What does negative predictive value indicate in diagnostic testing?
Negative predictive value indicates the proportion of individuals who have a negative test result and truly do not have the disease, reflecting the test's effectiveness in ruling out disease.
132
What are Patient Reported Outcome Measures (PROMs)?
Patient Reported Outcome Measures (PROMs) are tools that assess the experience of disease and health care directly from the patient's self-report, providing valuable insights into patient perspectives.
133
How do sensitivity and specificity relate to the performance of a diagnostic test?
Sensitivity and specificity are fixed characteristics of a diagnostic test that determine its ability to correctly identify individuals with and without the disease, respectively, impacting clinical decision-making.
134
What is the significance of understanding the positive and negative predictive values in clinical practice?
Understanding positive and negative predictive values is crucial in clinical practice as they help clinicians assess the likelihood that a patient has or does not have a disease based on test results, guiding treatment decisions.
