issues of reliability in the classification and diagnosis

What does it mean by reliability of diagnosis

Is The diagnosis of schizophrenia consistent?

• over time

• - between different doctors

Why is the reliability of diagnosing schizophrenia important

If the diagnosis is not reliable then there is an issue of whether or not schizophrenia is a valid illness

What are the 2 core tests of reliability

Inter rather reliability

• a psychiatric diagnosis is reliable when different clinicians read the same diagnosis*

Tests retest reliability

• when the same clinician gives a person the same diagnosis on 2 different occasions

What did OSORIO do in terms of reliability?

Reportexcellent reliability for diagnosis of schizophrenia in 180 individuals using DSM

Pairs of interviewers achieved inter-rather reliability of +0.97

Test retest reliability of +0.92

Suggests that we can be reasonably sure that diagnosis of schizophrenia can be consistently applied

What did URKIN do

How many psychiatrists did he ask to diagnose series of description patient history

URKIN et al

Asked 30 international psychiatrists to diagnose the conditions of a series of description of patient history

2 of which were schizophrenic

Only 10 out of 30 psychiatrists correctly identified and diagnosed the schizophrenic patients - suggests there are still issues for inter rather reliability

What is in support of different classification systems?

Cheniaux et al - investigated the inter rater reliability when using both the DSM 5 and ICD 10

Found a reliabilityof above 0.5 between 2 systems - suggests there is a fairly high level of reliability between the diagnosis systems

But it is still only 0.5 - suggests there are still patients who wouldn’t be indicated to have schizophrenia by both systems at the same time

What was excellent in terms of OSORIOS STUDY and clinicians

In osorios study agreement was excellent between clinicians when they diagnosed patients using the DSM. 5 - diagnosis has become more accurate

What version is ICD on

What has it been brought closer

What does it mean about new studies

ICD is on version 11

It’s been brought closer to the DSM 5 with the changes made

Means that new studies, which have not yet been run should finder greatr inter rater reliability