2. reliability and validity of diagnosis

Question 1

reliability in diagnosis and classification

Answer 1

consistency of a classification system e.g DSM V to assess symptoms of schizophrenia
must be repeatable so clinicians can’t reach the same diagnosis at different times (test-retest reliability)
different conclusions reach same conclusions (inter-rater reliability)- uses kappa score above 0.7=good

Question 2

validity in diagnosis and classification

Answer 2

extent the diagnosis represents something real and distinct from other disorders (criterion validity)
extent system measures what it intends
diagnosis can’t be valid if not reliable

Question 3

cultural differences in diagnosis
reliability
Copeland 1971

Answer 3

variations between countries influences diagnostic process
Copeland 1971: 134 US and 194 british psychiatrists a description of a patient. 69% US diagnosed schizophrenia vs 2% of british
BUT 1971= before DSM V, lacks temporal validity, current DSM V is more reliable

Question 4

cultural differences in diagnosis
reliability
Luhrman

Answer 4

hearing voices can be influenced by the cultural environment
60 adults with schizophrenia, 20 Ghana, India, US
African and Indian= positive experiences offering advise vs Americans= violent and indicating sickness
‘harsh, violent voices in the west not an inevitable feature= a lack of characteristics/ consistency

Question 5

cultural differences in diagnosis
reliability
subjectivity

Answer 5

hoped the DSM and ICD would give a standardised method of recognising mental disorders
interpreting behaviour= more subjective than hoped
eg Rosenhan

Question 6

reliability and validity
Rosenhan 1973

Answer 6

aim: how good diagnoses were using the DSM II if they were linked to symptoms or environment, should tell who has a real mental disorder vs not ‘pseudopatient’ who has 1 symptom then acts normally
procedure: him & 7 volunteers to range of hospitals pretending to have a single symptom: hearing voices saying ‘empty’, ‘hollow’, or ‘thud’
acted as patients
recorded responses from doctors
findings: all 8 to hospitals
all released with diagnosis
real patients said there was nothing wrong with them t doctors
doctors didn’t notice
doctors ignored there questions 71% of time
conclusion: environment= major impact on process of diagnosis, hospital not tell, after labelled a condition patients find it hard to escape label

Question 7

Rosenhan 1973
reliable? validity? DSM?

Answer 7

high reliability= all the same diagnosis
poor validity= weren’t diagnosed correctly
DSM II was in place, lacks temporal validity current DSM V more accurate diagnoses

Question 8

gender bias
validity

Answer 8

accuracy of diagnosis affected by gender
gender bias diagnostic criteria
basing beliefs on sterotypical beliefs

Question 9

gender bias
validity
abaroverman et al

Answer 9

diagnostic categories basied towards pathologising one gender
clinicns in the us based ‘healthy’ adult behaviour on healthy ‘male’ behaviour
= women seen as less mentally healthy

Question 10

rosenhan study 1973
AIM &PROCEDURE

Answer 10

how good diagnostic procedures were in DSM II
diagnosis really due to symptoms or affected by environment
clinicians should be able to tell the difference in suffering patient and mentally healthy pseudopatient
himself and 7 volunteers: 5 doctors/psychologists
range of hospitals reported single symptom voice saying: ‘empty’, ‘hollow’, ‘thud’
acted as model patients, co-operating with staff, wanted release asap, recorded responses of doctors and nurses

Question 11

rosenhan study 1973
FINDINGS & CONCLUSION

Answer 11

all 8 admitted to hospitals, average stay: 19 days, all released with diagnosis
real patients said nothing was wrong, staff didn’t listen
lack of response: doctors didn’t answer questions 71% of time, nurses only stopped to talk 0.5%of time
environment=major impact on diagnosis process
staff couldn’t tell mentally disordered from healthy
once labeled schizophrenic hard to escape label and be judged as ‘normal’

Question 12

rosenhan study 1973
EVALUATION

Answer 12

+ reliable, everyone got the same
diagnosis
- validity, none actually had schizophrenia but all diagnosed
- DSM II, not current DSM (V),lacks temporal validity

Question 13

validity
symptom over lap

Answer 13

positive & negative symptoms found in other disorders eg depression 7 bipolar disorder
Ellason 7 Ross= people with DID have more schizophrenic symptoms than diagnosed
Read= most diagnosed have sufficient symptoms of other disorders could have at least one other diagnosis

Question 14

validity
co-morbility

Answer 14

extent 2 or more conditions occur at the same time
Buckley et al= co-morbid depression 50%, substance abuse 47% (trying to self medicate?)
1% have S,2-3% have OCD Swets etal= 12% of S patients also fit OCD criteria,25% significant symptoms
conditions occurring frequently questions validity of diagnosis and classification, might actually be a single condition
if half also have depression maybe were just bad at telling them a part

Question 15

research
gender bias
loring and powell

Answer 15

Loring and Powell
290 male &female psychiatrists read case studies
make judgement using standardised diagnostic procedure
described as male 56% gave the diagnosis
female 20% diagnosed
gender bias was less from female psychiatrists
diagnosis influenced by gender or patient and clinician