Validity and Reliability of diagnosis

Question 1

Validity:

Answer 1

have we given the correct diagnosis/has the correct illness been diagnosed

Question 2

Reliability:

Answer 2

If they were diagnosed again would they get the same diagnosis

Question 3

Concurrent

Answer 3

Two separate test/measures give the same diagnosis i.e. DSM/ICD

Question 4

Construct

Answer 4

Do the symptoms in the DSM match up with the symptoms of the patient- your symptoms should match those listed for the illness I’ve diagnosed you with

Question 5

Predictive validity

Answer 5

We can suggest how your illness will progress (and we’re right) and/or I can give you medication for your illness and your symptoms should go away

Question 6

aetiological

Answer 6

you characteristics match up to what we expect about that illness i.e. genetic history of Sz

Question 7

Inter-rater

Answer 7

two different doctors give the same diagnosis

Question 8

Retest

Answer 8

You get the same diagnosis again when rediagnosed (could be on different versions of DSM…or just later on the same version)

Question 9

Things which effect V&R

Answer 9

• Standardised symptoms in diagnostic manuals e.g. in depression….
• DSM and ICD differences might lead to different diagnoses
• Co-morbidity (diagnosed as one by one and another by a different doctor)
• Updates to the DSM and ICD which might effect what illness you’re diagnosed as (either reliability or construct validity)
• Patients may lie/omit information
• Bias i.e. gender or racial bias
• Cultural bound syndromes
• Cultural differences may impact

Question 10

AO3- Rosenhan

Answer 10

(Good reliability (all but one) but bad for validity- patient’s lie)—validity point too because the nurses interpreted normal behaviours (bias)

Question 11

AO3- Kim-Cohen et al. (2005)

Answer 11

children diagnosed with conduct disorder were more likely to describe themselves are having antisocial behaviours than comparison children. Also, during observational assessments these children were more likely to behave disruptively. (Construct & Concurrent)

Question 12

AO3- Lee (2006)

Answer 12

ADHD in Korea Lee looked for concurrent validity by comparing the DSM-IV-TR criteria with criteria arising from the questionnaire, and compared DSM behavioural and psychological characteristics with those found in an ADHD test.

Question 13

AO3- Jakobsen et al (2005)

Answer 13

completed a random sample of Danish patients with schizophrenia. An ICD-10 diagnosis showed 93% sensitivity and 87% predictive value when diagnosing schizophrenia

Question 14

AO3- Kirk and Kutchins (1992)

Answer 14

In a review paper, Kirk and Kutchins argued that methodological problems with studies conducted to test the reliability of the DSM, they argued that there had been insufficient training and supervision of interviewers

Question 15

AO3- Goldstein (1988)

Answer 15

found that 169 of the 199 patients diagnosed according to DSM-II as having some form of schizophrenia met the DSM-III criteria too, so reliability was seen as good with the DSM. Of the patients assessed by the clinical experts as well, she found high levels of inter-rater reliability.

Question 16

AO3- Brown et al. (2001)

Answer 16

found good-to-excellent reliability for most of the DSM-IV categories (most of the disagreements tended not be on what the symptoms were, but simply if there were enough of them). However, they found some boundary problems with certain disorders, which made it hard to diagnose patients with disorders if they were at boundary level.

Question 17

AO3- Ford & Widiger (1989)

Answer 17

men and women with the same symptoms diagnosed with different illnesses (inline with stereotypes)

Question 18

AO3- Ward et al (1962)

Answer 18

IRR- 5% of inconsistencies due to patient giving faulty info, inconsistency in interpretation 32.5% and inadequacy of the classification system 62.5%

Question 19

AO3- Beck (1954)

Answer 19

The same set of symptoms were only diagnosed as the same disorder in about 50% of cases showing low reliability.

Question 20

AO3- Chandrensa

Answer 20

Catatonia seen in some countries more than others i.e. Sri Lanka Vs UK

Question 21

AO3- Sato

Answer 21

Japanese doctors less likely to diagnose SZ because its socially sensitive