reliability and validity in diagnosis and classification of Sz

Question 1

Define diagnosis (2m)

Answer 1

. identification of the nature of illness/other problems
. by examination of the symptoms
. e.g. someone reporting hearing voices

Question 2

Define classification (2m)

Answer 2

. action or process of classifying something
. classification of disease according to symptoms
. e.g. a symptoms of Sz is hallucinations

. what we use to form diagnosis - ICD11 and DSM5

Question 3

Reliability in diagnosis and classification of Sz

Answer 3

. reliability = consistency
. whether can gain consistent results when classifying and diagnosis Sz
. extent which different classification systems agree on how Sz should be classified
. and extent which 2+ health professionals agree on same diagnosis
. regardless of time period/culture
. measured by inter-rater reliability

Question 4

Validity in diagnosis and classification of Sz

Answer 4

. validity = accuracy
. are we measuring what we intend to measure (Sz)
. e.g. are classification systems accurately outlining signs/symptoms of Sz
. e.g. are health professional accurately diagnosing Sz or are we outlining different disease

Question 5

Cheniaux 2009

Answer 5

. asked two psychiatrists diagnose same 100 patients
. using DSM and ICD
. psychiatrist 1 - diagnosed 26=DSM and 44=ICD
. psychiatrist 2 - diagnosed 13=DSM and 24=ICD
. shows poor inter-rater reliability
. one psychiatrist diagnosed almost double the other
. shows poor reliability in classification of Sz
. both diagnosed almost double no. patients using ICD
. questions validity of diagnosis

• if 8m use as AO3 *

Question 6

Symptom overlap

Answer 6

. two or more conditions share similar symptoms
. e.g. both Sz and depression involve negative symptoms such as avolition

Question 7

Co-morbidity

Answer 7

. two illnesses/conditions occur at same time
. Sz commonly diagnosed with depression and/or OCD as share common symptoms e.g. low mood/motivation
. is a problem as mean Sz may not exist as distinct condition - may lead to misdiagnosis
. are not sure which condition came first so not sure which to treat first

Question 8

Gender bias

Answer 8

. since 1980s men diagnosed with Sz more often than women
. may be cause men more genetically vulnerable to developing Sz
. may be cause females with Sz typically function better - more likely work and have good family relationships

Question 9

Culture bias

Answer 9

. english people of African origin more likely diagnosed with Sz in UK
. rates in West Indies/Africa not high so cannot be due to genetic vulnerability
. higher diagnosis rates in UK may be cause some behaviours classified as positive symptoms of Sz are normal in African culture -
. e.g. hearing voices as part of ancestor communication
. cultural factors often not accounted for in diagnosis

Question 10

AO3 for reliability and validity of diagnosis and classification of Sz - symptom overlap

Answer 10

P - problem of reliability and validity of classification and diagnosis of Sz - often symptom overlap
E - where 2+ conditions share similar symptoms - e.g. Sz and depression involve negative symptoms (avolition)
E - questions validity/reliability of classification/diagnosis of Sz - person may be diagnosed wrong disorder - issue as doctors not diagnosing Sz correctly so not receive appropriate treatment
L - weakens reliability and validity of classification and diagnosis of Sz - negatively affects accuracy/consistency

Question 11

AO3 for reliability and validity of diagnosis and classification of Sz - co-morbidity

Answer 11

P - further problem reliability and validity of classification and diagnosis of Sz - co-morbidity
E - where two illnesses/conditions occur at same time
E - e.g. Buckley et al - concluded 50% patients diagnosed Sz also diagnosis of depression - 23% patients diagnosed SZ also diagnosis of OCD
L - questions reliability and validity of classification and diagnosis of Sz - cause two conditions may bet better seen as one - doctors may diagnosis wrong condition

Question 12

AO3 for reliability and validity of diagnosis and classification of Sz - gender bias

Answer 12

P - another issue reliability and validity of classification and diagnosis of Sz - gender bias in diagnosis
E - since 1980s men diagnosed with Sz more often than women - may be cause men more genetically vulnerable to developing Sz
E - however could be cause females with Sz typically function better - more likely work and have good family relationships - so symptoms may be masked by good interpersonal skills - Cotton et al
L - questions reliability and validity of classification and diagnosis of Sz - women who share similar symptoms as men not receive same diagnosis symptoms seen as mild

Question 13

AO3 for reliability and validity of diagnosis and classification of Sz - cultural bias

Answer 13

P - issue classification and diagnosis of Sz - cultural bias
E - english people of African origin - more likely diagnosed Sz in UK
E - attribute to Afro-caribbean societies - view hearing voices as communication from ancestors - WHEREAS UK is associated with positive symptom of Sz - so resulting in Afro-caribbeans living in UK being x10 more likely recieve diagnosis for Sz compared white Britons
L - questions reliability and validity of classification and diagnosis of Sz - classification of Sz depends on culture -meaning diagnosis maybe inaccurate