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Co-morbidity Exam > Clinical Trials > Flashcards

Flashcards in Clinical Trials Deck (22)
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1
Q

What is the order of clinical trial quality

A
MEta analysis
Systematic Review
Practie Guideline
Ransomised controlled trial
Cohort strudy
case control study
case report
2
Q

what is a case report?

A

Article that describes and interprets an individual case, often written in the form of a detailed story: - unique cases
Cases that show variation in a disease or condition
Cases that show may yield new or useful information

3
Q

what are the advantages of a case report?

A

¬ First line of evidence
¬ Cheap
¬ Educational
¬ Easy to take observations
¬ Good way of HCP communicating (SBAR report)
¬ Pharmacovigilance
¬ Can help with identification of new trends or diseases
¬ Help detect new drug s/e and potential uses
Identifies rare manifestations of a disease

4
Q

what are the disadvantages of a case report

A

¬ Cannot make a conclusion, only an observation
¬ Cannot establish a cause and effect relationship (as only a small number of cases)
¬ Lowest level of evidence
¬ Cases may not be generalised
¬ Not cased on systematic stidies
¬ Causes or associations detailed may have other explaations, danger of misinterpretation
Journals may be biased

5
Q

what is a case controlled study

A

Compares patient cases that have had the disease with controls (patients that don’t have the disease). Compare how frequently the exposure to a risk factor is present in each patient group to determine the relationship between risk factor and the disease .
Used to estimate odds

6
Q

what are the advantages of a case controlled study?

A

¬ Quick
¬ Cheap
¬ Easy to form
¬ Suitable for studying risk factors associated with rare diseases
¬ Good to do a wee study before a big one
¬ Simultanrously look at many risk factors
Answer questions that you may not be able to answer through other study designs

7
Q

what are the disadvantages of a case controlled study?

A

¬ Prone to bias
¬ Recall bias on past behavours
¬ Rely on emory
¬ Subjective
¬ Not efficient to form cause and analysis
¬ Can be difficult to find suitable control group
¬ Control group may be over selected
¬ Results are determined by recall (memory of person)
May be flaw in relationships between disease and risk factors (confounding influence)

8
Q

what is a cohort study?

A

Follow cohorts and status evaluations are made with regard to disease or outcome to determine which of the initial risk factors the participant was exposed to are related to the disease (risk factors)

As the study is conducted outcome from participants in each cohort is measured and relationships with specific characteristics is determined

Difference between cohorts already exists (e.g. man/woman) the difference isn’t imposed upon them like in a clinical trial)

9
Q

what are the advantages of a cohort study?

A

¬ Examine multiple events associated with exposure
¬ Subjects in cohorts can be matched (to limit the influence of confounding variatbles)
¬ Standardisation of criteria outcome is possible
Easier and cheaper than randomised controlled trials

10
Q

what are the disadvantages of a cohort study?

A

¬ Expensive
¬ Time cosuming
¬ Not good for rare cases or cases that take a long time to develop
¬ Selection bias (can manipulate individuals in cohorts to achieve a specific outcome)
¬ Cohorts can be difficulat to identify due to confounding variables
¬ No randomisation so imbalances in patient characteristics could exist
¬ Blinding/masking is difficult
¬ Outcome of interest could take time to occur
Look for secondary characteristics of the participants that could influence disease being studied for (e.t. people that drink linked to lung cancer but the people that drink also smoke)

11
Q

what is a randomised controlled trial

A

Study design that randomly assigns participants into experimental group or a control group.

One group has a medicine and the other has a placebo

As the study is conducted the only expected difference between the control and experimental group in a randomised controlled trial (RCT) is the outcome variable being studied

12
Q

what are the advantages of a randomised controlled trial?

A

¬ No bias
¬ Easy to “blind” if you use a placebo
¬ Analused with well known statistical tools
¬ Good randomisation without any population bias
¬ Easier to make blind than observational studies
Populations of participating individuals are clearly identified

13
Q

what are the disadvantages of a randomised controlled trial?

A

¬ Expensive and time cosuming
¬ Can be volunteer bias (population that participates may not be representative of the population as a whole)
¬ Can be subject to personal and political pressure
¬ Personal and political influences
¬ Confounding variables
¬ RCT should be a study of one population only
¬ Population that is involved shouldn’t know that the medicine they are taking is or what it is for
¬ Is the randomisation actually random
Baseline characteristics should be taken first

14
Q

what is practice guidelines

A

A statement produced by a panel of experts that outlines current best practive to inform healthcare professionals in making clinical decisions .

Produced after a extensive systematic literature review

15
Q

what are the advantages of practice guidelines

A
¬	Summarise best evidence
¬	Prevention
¬	Diagnosis
¬	Prognosis
¬	Therapy
¬	Harm
¬	Cost effectiveness 

¬ Provides standardised guidelines for practitioners to use
¬ Statement produced after review of lots of evidence
¬ Summarise the best evidence
¬ Identify where information is intergraded into practice
¬ Created by panel of experts
¬ Evidenced based resource
¬ Taken from good quality evidence (RCT, systematic analysis, meta analysis)

16
Q

what are the disadvantages of practice guidelines

A

¬ Can go out of data and should be reviewed frequently and updated as necessary for continued accuracy and relevancy

¬ Guidelines aren’t always available for controversial or less common topics

¬ Not individualised ofr every patients

Should ensure there are many differnet healthcare professionals on the guideline board to ensure balanced opinion is reached

17
Q

what is a systematic review

A

Docuent written by a panel
Provides a comprehensive review of all relevant studies on a particular clinical or health related topic/question

Systematic review is created after reviewing and cobining all information from published and unpublished studies then summarising the findings

18
Q

what are the advantages of a systematic review

A

¬ Regarded as the strongest form of medical evidence
¬ Summarise large bodies of evidence
¬ Minimise bias
¬ Reduce researcher bias
¬ Improves likelihood of generating a clearer more objective answer to research question
¬ Exhaustive review of current literatyre and other sources (including published, unpublished studies and ongoing research)
¬ Less costly to review prior studies than to create a new study
¬ Results can be generalised and extrapolated to the general population more broadly than individual studies
¬ More reliable and accurate than individual studies
Consider as anevidence based resource

19
Q

what are the disadvantages of a systematic review

A

¬ Very Time consuming
¬ Editors going through all the trials may still be biased and could chose ones they want to include and miss out ones they don’t want to
¬ May not be easy to compare studies especially if they are studying different variables

¬ Studies included in systematic reviews may be of varying study design but could collectively be studying the same outcome
¬ Is each study included in the review studying the same variable
¬ Some reviews may group and analyse studies by variables such as age and gender, facors that weren’t allocated to the participants
¬ Do the analysis in the systematic reiew fit the variables being studied in the original studies
¬ Consider inclusion/exclusion criteria of the studies
¬ How good are the studies that are included
The systematic review will only be as good as the studies that are included

20
Q

what is a meta analysis

A

Statistical analysis that combines the results of multiple scientific studies

It is a subset of systematic reviews

Method for systematically combining pertinent qualitative and quantative study data from several selected studies to develop a single conclusion that has greater statiscial power

21
Q

what is the advantages of a meta analysis

A

¬ Statistically stronger than the analysis of a single study due to the increased numbers of subjects, greater diversity amoung subjects or accumulated effects and results
¬ Used to establishe statiscical significance with studies that have conflicting results
¬ Develop a more correct estimate of effect magnitude
¬ Provide a more complet analysis of harms, safety data and benefits

If the study utelised RCT (randomised controlled trials) , comning several RCT results would be the highest level of evidence on the evidence hierarchy, (followed by systematic review) which analyse all available studies on a topic

¬ Confirmatory statistical data analysis
¬ Can extrapolate to include other populations
¬ Stronger form of evidance than single trials
¬ Greater statistical power

22
Q

what is the disadvantages of a meta analysis

A

¬ Difficulat and time consuming
¬ Requires statistician and advanced statistical techniques
¬ Got to all have the same type of stifues (e.g all must be RCT)
¬ Not good if use a mixture of different study types
¬ Analysis should include published and unpublished results
Meta analysis should also include appropriate relevant studies that have had a negative outcome