Week 5-8 Flashcards
Name the 7 threats to Internal Validity
Bias from the assessor Recall bias Placebo effect Hawthorne effect Natural recovery/maturation Regression to the mean Process of treatment
How do researchers manage threats to validity?
Control group
Define: Blinding
means not knowing who is receiving the true intervention, and who is receiving the control
Which level of evidence reduces the potential for bias, increases internal validity and has better strength of evidence
The evidence further up the hierarchy of evidence
What type of evidence is the lowest level of evidence?
Expert Opinion
If the Exposure is ‘known’ and the outcome is ‘unknown’ what type of evidence is this?
Cohort
If the Exposure is ‘unknown’ and the Outcome is ‘Known’ what type of evidence is this?
Case control
Name the Levels of Evidence in order of best evidence to lowest level of evidence
- Clinical guidelines/summaries
- Systematic reviews
- RCT’s
- Non-RCT’s
- Cohort studies
- Case control studies
- Case series/time series
- Case reports
- Expert opinions
Explain: Case series
- same as a case study but more than one person
- group of people usually measured before and after intervention but has no control group
Explain: Case-control study
- used to evaluate relationships, treatments and cause of disease
- Is retrospective (looks back in time)
- Compares history & exposure of people who have a condition with those that don’t
Explain: Cohort study
- Is prospective (looks forward in time)
- compares the progress of people who are exposed and/or receive a particular treatment and a control group
- epidemiological research design
Explain: RCT
- most rigorous design of health research to determine whether a cause-effect relationship exists
- not always ethical/feasible (so cohort or case control might be necessary)
Explain: Systematic Review
- combines more than one primary study for any research question
- bias is minimised here
- critically appraises studies
- combines studies statistically (if possible) which is called a meta-analysis
Explain: Summaries or Guidelines
- asks clinical questions
- summarises evidence for a topic
- provides evidence-based guidelines for practice
- are reviews of systematic reviews
What is an intervention?
Anything that can have a cause and effect but usually means a treatment
Define: Ethics
‘how we ought to live’
What are the Universal Principles of Ethics
Autonomy
Non-maleficence
Beneficence
Justice
Name the 2 types of Ethical Theory
Deontology
Teleology
Define: Deontology
Intrinsic ethical absolutes
Define: Teleology
Relative consequentialism
Give an example: Deontology
Taking a life is always wrong
Give an example: Teleology
taking a life might be right or wrong depending on the circumstances
What are the 3 main applications of Ethical Theory
Altruism- best consequences for others
Egoism- best consequences for an individual
Utilitarianism- best consequences for the greatest number
When ethical issues present in health it is refer to as…
Bioethics
What are the principles included in the Nuremberg Code
- voluntary informed consent
- absence of coercion
- properly formulated experimentation
- beneficence towards experiment participants
When was the International Ethical Guidelines for Biomedical Research Involving Human Subjects developed?
1982
Who developed the ‘International Ethical Guidelines for Biomedical Research Involving Human Subjects’
CIOMS- Council for International Organisations of Medical Science
and WHO
In Australia, when did ethics guidelines development begin?
1960’s
Define: HREC
Human Research Ethics Committee
Define: Protocol
The research plan- how the research will be conducted in detail
Define: Representative Sample
means that all those who should be represented, are reflected in the sample
Define: Parameter
is the measure or descriptor that applies to the Population or target group
Define: Statistic
is a measure or descriptor that applies to the Sample group
Define: Random Sampling
is when all members of the population have an equal chance of selection
Define: Reliability
is the reproducibility of the results of a procedure or tool
Define: Variable
the item of interest or thing we are measuring
Define: Measurement
is the process of quantifying this variable (item being measured)
What are the 3 Error Types in measurement
Sources of error
Types of error
Types of reliability
Give an example: Sources of error
- Equipment
- Patient/participant
- Measurer/researcher
Name the 2 Types of Measurement Error
- Systematic errors
- Random errors
Give an example: Types of reliability errors
- test-retest reliability
- Intra-rater reliability
- Inter-rater reliability
Define: Test-retest reliability
to establish that a measurement instrument is capable of obtaining the same results with consistency
Define: Intra-rater reliability
the stability of data recorded by one individual across two or more trials
Define: Inter-rater reliability
the stability of data recorded by more than one individual in one trial
Define: Correlation
measures the strength of association between two variables
Is a common measure of association
Name the 3 types of validity
Measurement validity
Internal Validity
External Validity
Define: Measurement validity
the degree to which a test actually measures what it is meant to measure
(Measurement Validity)
Name the 3 reasons we measure things
- Discriminate between individuals
- Evaluate change in the magnitude or quality
- Predict make useful and accurate predictions or diagnoses about a patient/client/group
Define: Validation
the degree of confidence we have in the inferences (results) we draw from test measurements
(Measurement Validity)
Name the 4 ways you determine the type of validity
- Face validity
- Content validity
- Construct validity
- Criterion validty
(Measurement Validity)
Define: Face validity
People think that it measures what it is supposed to measure
- lowest form of validity
(a subjective assessment based on personal opinions of people giving or taking the measurement)
(Measurement Validity)
Define: Content validity
the ability of an instrument to represent all content areas of importance in a test
- usually assessed by a panel of experts
(Measurement Validity)
Define: Construct validity
The test correlate with other tests that measure the same thing
(Does the measurement correlate well with other measures of the same thing and not correlate with measures of other things)
(Measurement Validity)
Define: Criterion validity
Definition: the measurement can be used as a substitute measure for an established, or ‘gold standard’ measure of the same thing
Easier Definition: is when we measure using our scale against a “gold standard” scale (this is a proven scale for measuring a specific condition)
Describe the difference between the 4 types of validity
Face, Construct and Content validity: determined by logical argument
Criterion validity: determined by direct testing
Explain Reliability and Validity
- A measure can be reliable but not valid
- A measure cannot be valid if it is not reliable
What types of research uses Measurement Validity
Aetiology studies
Intervention studies
Prognosis studies
Diagnostic test studies
Define: Internal Validity
measures how much we can trust that research conclusions are correct and true
Define: External validity
is the extent to which the results of research can be generalised to other samples or situations (generalisability)
What does it mean when there is strong internal validity?
we can trust the conclusions are true
Threats to Internal Validity
Explain: Placebo effect
is the improvement due to only experiencing an intervention or event, whether real or not
Threats to Internal Validity
Explain: Hawthorne effect
an improvement due to participants being studied, not the intervention
Threats to Internal Validity
Explain: Natural Maturation/Recovery
the condition improves irrespective of the treatment
Threats to Internal Validity
Explain: Regression to the mean
patients with episodic disease present for intervention when condition is severe, but from here fluctuations are likely to be less severe
Threats to Internal Validity
Explain: Process of treatment
- politeness and positivity
- psychological effects between healer and patient
