Reliability and Validity of classification and diagnosis Flashcards
Reliability in disgnosis
consistency of ‘something’
inter-rater reliability - whether diff clinicians make identical, ind diagnoses of same patient.
test-retest reliability- whether same diagnosis made on separate occasions from same info
Validity in diagnosis
extent to which we’re measuring what we intend to measure
is it truthful?
is it accurate?
criterion validity - assess validity of diagnosis. do diff assessment symptoms arrive at same diagnosis?
(ICD 10 ans DSM-5 same diagnosis)
Cheniaux et al (2009)
had two psychiatrists independently diagnose 100 patients using both DSM and ICD criteria.
Cheniaux et al - inter-rater and criterion
they were both was poor.
-one psychiatrist diagnosed 26 with DSM and 44 with ICD
-other 13 with DSM and 24 with ICD
Co-morbidity
-occurrence of 2 or more medical conditions together. (e.g schiz + bip)
-in conditions occur together a lot of the time, questions the validity of their diagnosis and classification as they might actually be 1 single condition rather that 2 seperate.
Buckley et al (2009)- Co-morbidity
-review of ppl with schizophrenia.
-of these: 50% also had depression, 47% also had substance abuse, 29% also had PTSD, 23% also had OCD.
-DIAGNOSIS- if 50% of those diagnosed with schiz also have depression, clinicians may be bad at telling diff between the two.
-CLASSIFICATION- if v severe depression looks like schiz (vice versa) may be single condition.
Symptom Overlap
-Occurs when 2 or more conditions share symptoms.
-e.g bipolar and schiz disorder involve delusions and abolition.
-under ICD patient may be diagnosed as schiz but be diagnosed with bipolar using DSM.
Ophoff et al (2011)- Symptom Overlap
-assessed genetic material from 50,000 participants.
-of 7 gene locations on gene associated with schiz 3 of them were associated with bipolar.
-genetic overlap between disorders
-two may be one disorder. may mean ppl being labelled with wrong mental health illness and may not be getting appropriate treatment.
Gender bias
-tendency for diagnosis criteria to be applied differently to males and females.
-gender of patient may impact diagnosis.
-psychiatrists gender might impact their ability to diagnose.
Longnecker et al (2010) - gender bias
-reviewed studies of the prevalence of schiz.
-concluded that since 1980s more men been diagnosed with schiz than women.
-there had been no diff prior to this
-males more genetically vulnerable
-females tend to function better than men - more likely to work + have better interpersonal skill. high functioning may have prevented diagnose.
-doctors may be misapplying classification system based on gender.
culture bias
-tendency overdiagnose members of other cultures.
-calls into question reliability and validity of diagnosis.
-suggests patients display same symptoms but receive diff diagnoses due to background.
-ethnicity more/less likely that person will be diagnosed.
culture bias - African
-in Britain Afro-Caribbeans more likely diagnosis and more likely to be in secure unit.
-cant be due to diff in genetic vulnerability as rates of schiz aren’t higher in Africa and West Indies.
-hearing voices more acceptable in African culture because of cultural beliefs in communication with ancestors. if reported to a clinician with diff cultural background can be seen as bizarre and irrational.
Escobar (2012)- Culture bias
found white psychiatrist tend to over-interpret symptoms and distrust the honest of black ppl during diagnosis.
