8. Use of pertinent treatment guidelines 3 Flashcards
What is a cohort study?
A cohort study is an observational study design that involves monitoring a large number of individuals over a long period of time commonly years to compare incidence rates of diseases or outcomes in groups that differ based on their exposure levels. It allows researchers to observe the natural progression of diseases and the effects of risk factors.
What does ‘concealment of allocation’ mean in the context of a clinical study?
‘Concealment of allocation’ refers to the precautions and methods employed to ensure that the groups to which participants are assigned in a study remain undisclosed prior to their actual allocation. This process helps minimize bias in the assignment of participants to ensure the integrity of the study process.
Define ‘confounding variable’ and explain its significance in research.
A confounding variable is an extrinsic factor that is correlated with both the exposure being studied and the outcome of interest. Its presence can distort the apparent relationship between the exposure and outcome making it difficult to ascertain causation. Recognizing and controlling for confounding variables is crucial to obtaining valid research results.
What is a cross-sectional study and what does it measure?
A cross-sectional study is a type of observational research that looks at the relationship between diseases or health-related characteristics and other variables of interest within a defined population at a specific point in time. It primarily measures disease prevalence rather than incidence and it cannot adequately establish temporal relationships between causes and effects.
What is the difference between disease prevalence and disease incidence as recorded in studies?
Disease prevalence refers to the total number of existing cases of a disease in a population at a specific time while disease incidence measures the number of new cases that develop in a population over a defined time period. Cross-sectional studies typically focus on prevalence.
What is a diagnostic test?
A diagnostic test is any medical procedure or examination used to determine the presence or absence of a disease condition or health issue in a patient. These tests may include laboratory tests imaging studies and physical exams.
What is the purpose of diagnostic tests?
Diagnostic tests are performed to confirm or determine the presence of disease in an individual suspected of having the disease. Typically this is done following the report of symptoms or based on the results of other medical tests.
Give two examples of diagnostic tests.
- A chest x-ray to diagnose pneumonia. 2. A skin biopsy to detect cancerous cells.
Define ‘disease incidence’.
‘Disease incidence’ refers to the measure of new cases of a disease or condition occurring in a specified population over a particular period of time.
Define ‘disease prevalence’.
‘Disease prevalence’ refers to the total number or rate of cases of a disease or condition present in a population at a specific point in time.
What does ‘expert opinion’ mean in a medical context?
‘Expert opinion’ refers to a determination made by experts through an evidence-based process recommending whether a particular medical practice should or should not be performed. This opinion is typically published in a peer-reviewed medical journal.
What is an inception cohort study?
An inception cohort study is a type of research design where a group of individuals is identified for subsequent study at an early uniform point in the course of a specified health condition or even before the condition develops.
What is defined as the ‘index test’?
The ‘index test’ is the diagnostic procedure or test being evaluated in a study to determine its accuracy or effectiveness in diagnosing a particular disease or condition.
What does ‘Intention to treat’ mean in the context of randomized controlled trials?
‘Intention to treat’ is a principle in the conduct and analysis of randomized controlled trials where all patients allocated to a given arm of the treatment regimen are included in the analysis regardless of whether they received or completed the prescribed regimen. This approach is critical for preserving the benefits of randomization and ensuring the validity of the study results.
What are the consequences of not adhering to ‘Intention to treat’ analysis in clinical trials?
Failure to follow ‘Intention to treat’ analysis can defeat the main purpose of random allocation leading to biased results and potentially invalid conclusions about the effectiveness of the treatment under study.
What does ‘Low risk of bias’ refer to in clinical trials?
‘Low risk of bias’ refers to trials or studies that have methodological safeguards in place to protect against various biases including those arising from financial interests academic interests industry influence and other issues related to the randomization sequence allocation concealment selection bias blinding selective outcome reporting early stopping and adherence to the intention to treat principle.
What are some factors that can contribute to bias in clinical trials?
Factors that can contribute to bias in clinical trials include: vested financial interests academic biases influence from the industry improper generation of randomization sequence lack of allocation concealment selection bias improper blinding selective reporting of outcomes and premature stopping of trials.
Define ‘Meta-analysis’.
Meta-analysis is a mathematical process that combines results from two or more studies using a method that provides weights to each study based on their statistical significance and reliability allowing for a more comprehensive understanding of the overall efficacy of a treatment or intervention.
What is the importance of the statistical weighting in a meta-analysis?
Statistical weighting in a meta-analysis is important because it accounts for the varying sizes and precisions of individual studies ensuring that larger more reliable studies have more influence on the overall results than smaller less reliable studies.
What is a ‘randomized controlled trial’ (RCT)?
A randomized controlled trial (RCT) is a study design that randomly assigns participants to either a treatment group or a control group allowing researchers to evaluate the effect of an intervention while minimizing biases and confounding variables.
Why is randomization important in clinical trials?
Randomization is important in clinical trials because it helps to eliminate selection bias ensuring that treatment groups are comparable and that the results can be attributed to the intervention rather than to differences between the groups.
What is allocation concealment and why is it important?
Allocation concealment is the practice of keeping the allocation sequence hidden from participants and researchers until the moment of assignment. It is important to prevent selection bias ensuring that neither participants nor researchers can influence which treatment group participants are assigned to.
What is the role of blinding in clinical trials?
Blinding in clinical trials refers to the practice of keeping participants caregivers and/or researchers unaware of which participants are receiving the treatment or control which helps to minimize bias in treatment administration reporting and outcome assessment.
What is likelihood variance?
Likelihood variance refers to the extent to which the observed results of a study are expected to vary from the true value or parameter being estimated. A lower likelihood variance indicates that the results are more likely to be closer to the truth.