reliability and validity of diagnoses Flashcards
validity of diagnosis
diagnosis must genuinely reflect underlying disorder
concurrent validity
comparing evidence from several studies testing the same thing to see if they agree e.g. looking at another diagnostic tool
aetiological validity
extent to which diagnosis reflects known causes such as family history in a disorder that is known to have a genetic cause
predictive validity
extent to which results from a test can predict future behaviour. So diagnosis can be checked against outcome to see if its valid
implicit biases and example
positive or negative mental attitude towards something that a person holds at unconscious level
e.g. clinician may be more ready to diagnose females with depression as it is more prevalent in females
comorbidity
the presence of more than one disorder in the same person at the same time
reliability of diagnoses
the extent to which clinicians agree on the same diagnoses form the same patient
why might diagnoses be unreliable
SE
because diagnosis is complex as symptoms occur across different disorders so 2 clinicians might see the same symptoms but assign different disorders
Ward et al 1962: studies 2 psychiatrists diagnosing the same patient
inconsistency of info provided by patient = 5%
inconsistency of psychiatrists interpretation = 32.5%
- main reliability issue was diagnostic tool used
inter-rater reliability
SE
the degree of agreement and consistency between raters about the thing being measured
= showing 2+ clinicians a persons history and assessing the level of agreement
Beck 1954: found same symptoms were only diagnosed as the same disorder in about half of cases = low reliability
patient factors
inaccurate info due to:
- memory, denial, shame
- disorganised thoughts, psychopathy
clinician factors
- unstructured nature of interviews can lead to looking at certain symptoms
- subjective judgement and interpretation which depends on background, training and experiences
