Reliability and validity in diagnosis and classification

Question 1

What is reliability for Sz

Answer 1

Diagnosis must be repeatable

Question 2

What is test retest reliability for Sz

Answer 2

The same clinitian must reach the same conclusion at different points in time

Question 3

What is inter-rater reliability for Sz

Answer 3

Different clinitians must reach the same conclusion

Question 4

What is a good kappa score for reliability of diagnosis

Answer 4

0.7

Question 5

Why might there be cultural differences in diagnosis of Sz

Answer 5

-Copeland gave 134 US and 194 British psychologists a description of a patient. 69% of the US ones said they had Sz while only 2% of British did
-Luhrmann interviewed 60 adults diagnosed with Sz 20 from Ghana, 20 from India and 20 from the US. The African and Indian subjects often heard positive advice from their voices while the Americans did not

Question 6

Who checked the inter rater reliability of US and British psychologists

Answer 6

Copeland

Question 7

Who found african and indians heard nice voiced

Answer 7

Luhrmann

Question 8

Why may gender bias threaten the validity of Sz diagnosis

Answer 8

Gender biased diagnostic criteria or clinitians may lead to judgements being based on seriotypes of a gender. Rotherman found women were less likely to be diagnosed because their abnormal behaviour was more likely to be ignored

Question 9

Why is symptom overlap an issue for validity of diagnosis

Answer 9

Many Sz symptoms are found in other disorders, with Ellason and Ross pointing out that people with Dissociative Identity Disorder (DID) actually have more Sz symptoms than those with Sz

Question 10

Who found women were naturally sorta insane so less likely to be diagnosed

Answer 10

Rotherman

Question 11

Whoclaimed those with DID had more symptoms of Sz than those with Sz

Answer 11

Ellason and Ross

Question 12

What is co-morbidity

Answer 12

When two or more conditions co-occur

Question 13

Why is comorbidity an issue for validity of Sz diagnosis

Answer 13

Co-morbidities are common among those with Sz, with Buckley estimating that co-morbid depression occurs in 50% of patients, and 47% also having a lifetime diagnosis of co-morbid substance abuse

Question 14

Who found lots of comorbidity with Sz patients

Answer 14

Buckley et al

Question 15

How is lack of inter-rater reliability an issue for diagnosing Sz (eval)

Answer 15

Over the last 30 years there has been little evidence that the DSM is routinely used with high reliability. Whaley found inter-rater reliability correlations as low as 0.11. Rosenhans ‘sane in insane places’ also show poor inter rater reliability with the fact that some pseudopatients were released and others weren’t

Question 16

Who found inter-rater reliability of 0.11

Answer 16

Whaley

Question 17

Who did ‘sane in insane places’

Answer 17

Rosenhan

Question 18

What is a real world difference with culutral differences in diagnosis of Sz (eval)

Answer 18

The ethnic culture hypothesis suggests that ethnic minority groups experience less distress associated with Sz because of the protective characteristics and social structures that exist within these cultures. Brekke and Barrio found evidence to support this hypothesis in a study of 184 Sz sufferers. Those in minority groups were less symptomatic than those not in these groups

Question 19

Who found minorities are less symptomatic than the majority

Answer 19

Brekke and Barrio

Question 20

What is research support for the issues of gender bias in diagnosis (eval)

Answer 20

Loring and Powell randomly selected 290 male and female psychologists to read two cases of patient behaviour. If the patient was described as ‘male’ or no gender was given, 56% gave a diagnosis of Sz. If the patient was female, 20% gave a diagnosis. This difference wasn’t present in female psychologists

Question 21

Who found evidence of gender differences in diagnosis

Answer 21

Loring and Powell

Question 22

How does prognosis of patients impact validity of diagnosis (eval)

Answer 22

There is no evidence that those diagnosed with Sz share the same outcomes. Only 20% recover to their previous levels and about 30% show improvement. A diagnosis of Sz therefore has little predictive validity. Gender and psychological factors do seeom to influence recovery

Question 23

How does prognosis of patients impact validity of diagnosis (eval)

Answer 23

There is no evidence that those diagnosed with Sz share the same outcomes. Only 20% recover to their previous levels and about 30% show improvement. A diagnosis of Sz therefore has little predictive validity. Gender and psychological factors do seeom to influence recovery