Reliability and Validity Flashcards
Define reliability
Consistency across results, measuring tools and procedure over time
Define validity
The data aims to accurately measure what it intends to measure
What is a classification?
Symtoms (severity and duration) that are under the label to meet a criteria
What is diagnosis?
Application of the classification (criteria) by a psychiatrist in order to treat or enforce positive practical application (i.e. accessibility through education or lifestyle) of the disorder
What is the rule when it comes to reliability and validity?
For something to be reliable, it does not have to be valid. But for something to be valid it has to be reliable.
What is inter-rater reliability?
Where the same diagnosis is given by multiple psychiatrists
What is test-retest check?
Where diagnosis should be the same over a given period of time
Why is the reliability of classification distorted?
It is not consistent over time:
* DSM-IV negative symptoms included affective flattening, alogia and avolition whereas in DSM-V they include diminished emotional expression and avolition
* DSM-V: schizophrenia cannot be classified if only symptom is held with a bizarre delusion or hallucination
* DSM-V: removes subtypes of schizophrenia
What is the magic number of reliability?
80% or 0.8
Speak suggestively and tentatively
Outline schizophrenia and reliability
Classification
Make it clear the difference between classification and diagnosis
Criteria should stay the same over time, across different psychiatric manuals
* If the classification of schizophrenia were reliable; identical criteria across both manuals (ICD and DSM)
Speak suggestively and tentatively
Outline schizophrenia and reliability
Diagnosis
Make it clear the difference between classification and diagnosis
- If the same patient were to be seen by multiple clincians, we should expect to see the same diagnosis (inter-rater reliability), indicating high levels of reliability
- If inter-rater reliability is high, the same patients would receive the same diagnosis by different clinicians f 80% or highers
- If the diagnosis of schizophrenia were reliable, we would expect it to score highly on a test-retest check, i.e. if the same patients present the same symptoms, the diagnosis should remain the same
Speak suggestively and tentatively
Outline schizophrenia and validity
Classification
Make it clear the difference between classification and diagnosis
- If schizophrenia’s classification were valid, we would expect to see its criteria measuring the symptoms of schizophrenia and not that of other disorders (distinct and discrete)
- Low leveps of symptoms overlap and co-morbidity, i.e. schizophrenia with addicition, or a personality disorder
To be high in validity, it must also be high in reliability
Speak suggestively and tentatively
Outline schizophrenia and validity
Diagnosis
Make it clear the difference between classification and diagnosis
In order for the diagnosis of schizophrenia to be valid, its classification must be valid
What is required for the classifcation of schizophrenia to be considered reliable?
An identical criteria across different psychiatric manuals
DSM and ICD
What is required for the diagnosis of schizophrenia to be considered reliable?
High inter-rater reliability and test-retest check
Contextualise to schizophrenia
