Reliability And Validity Flashcards
What is reliability in the context of diagnosis?
Consistency of diagnosis
Reliability refers to the consistency of a diagnosis across different instances or evaluators.
Define validity in terms of diagnosis.
How accurate a diagnosis is
Validity assesses the accuracy and effectiveness of a diagnosis in predicting outcomes.
What is predictive validity?
Diagnosis will lead to successful treatments
Predictive validity measures whether a diagnosis can forecast successful treatment or recovery.
Explain inter-rate reliability.
Different clinicians will give the same diagnosis
Inter-rate reliability evaluates the agreement between different clinicians diagnosing the same patient.
What does descriptive validity refer to?
The extent to which a diagnosis matches patient symptoms
Descriptive validity ensures that the diagnosis accurately reflects the symptoms presented by the patient.
Reed et al (limitation of reliability)
This study involved 194 British and 130 US psychiatrists providing diagnoses based on a key study. They found that 69% of US psychiatrists diagnosed individuals with Sz compared to only 2% of the patients being diagnosed by British psychiatrists. Suggests low inter-rater reliability
Rosenhan’s study ‘Being Sane in Insane Places’
Rosenhan’s study involved pseudo patients who were admitted to mental hospitals, leading to significant questions about diagnostic accuracy.
Found out of the 8 pseudo patients admitted, 7 were given a diagnosis of sz
Concluded psychiatrists cannot distinguish between real and pseudo patients
What is the significance of high descriptive validity?
It improves the reliability of diagnoses
High descriptive validity indicates that a diagnosis is accurately reflecting the symptoms and conditions of the patient.
Jäger et al (strength of validity)
P-High descriptive validity
E-Distinguished 1000 cases of sz patients, found more pronounced negative symptoms and lower overall functioning.
E-Therefore high validity bc distinguished key differences in sz symptoms from other disorder.
What percentage of people recover from the sz according to Birchwood and Jackson?
20%
The study indicates significant variability in recovery outcomes among patients.
What is the suicide rate mentioned in the findings of Birchwood and Jackson?
10%
This statistic underscores the serious risks associated with mental health diagnoses and treatment outcomes.
Limitation: low predictive validity
P- Different patients experience a wide range of symptoms
E- Birchwood and Jackson: found that 20% people with sz recover and never have another episode and 10% commit suicde.
E- Treatments may be successful but diagnosis is not valid or vice versa so all treatments may not work for all.
L- Too much variety in outcomes of sz suggesting diagnosis has low validity
What is culture bias?
Tendency to over-diagnose members of certain cultures
Culture bias can affect how disorders are diagnosed across different cultural contexts.
Define alpha bias.
Exaggerates differences between diagnoses
Alpha bias can lead to misinterpretations of symptoms across cultures.
Define beta bias.
Downplays differences between cultures
Beta bias may cause underdiagnosis or misinterpretation of symptoms in certain cultural groups.
What is androcentrism?
Bias of psychological research where a culture is overemphasised
This can skew understanding and diagnosis of disorders in different cultural contexts.
What is co-morbidity?
Where one or more disorders crossing over
Co-morbidity can complicate the diagnosis of individual disorders.
Limitation: Jeste
Sz patients with co-morbid conditions are excluded from research yet form majority of patients
This exclusion reduces the generalisability of research findings.
Sim et al (co-morbidity)
32% of 142 patients with sz had an addictive mental disorder
This statistic highlights the prevalence of co-morbid conditions in schizophrenia patients.
Issues with reliability of diagnosis
What is gender bias in relation to schizophrenia diagnosis?
Up to 50% more males than females diagnosed
Gender bias can influence how diagnoses are made and perceived.
What is the significance of female sex hormones in schizophrenia treatment according to Kulkai?
Effective in treating schizophrenia in women
This suggests biological differences may necessitate different treatment approaches.
What did Lewin et al. find regarding gender bias in schizophrenia diagnosis?
Less females diagnosed compared to males
This indicates a potential bias in the diagnostic process.
What is symptom overlap?
Symptoms of one disorder overlap with another disorder
How does symptom overlap affect the diagnosis of schizophrenia?
Symptoms of one disorder overlap with another disorder
This can complicate accurate diagnosis. Especially with bipolar and depression
What did Konstantareas and Hewitt find in their comparison of autism and schizophrenia patients?
No schizophrenia patients showed autism symptoms, but half of autism patients showed schizophrenia symptoms
This highlights the diagnostic challenges between these two conditions.
What is the relationship between brain scans and schizophrenia?
People with schizophrenia have decreased grey matter
This is in contrast to bipolar disorder, which does not show the same brain matter changes.
Strength of gender bias
Differences between gender could be caused by differences in stress e.g. menopause
Supports idea sz is biological
Test-retest reliability
All patients will have the same diagnosis if they show the same symptoms
Strong reliability (of diagnosis)
Diagnosis comes from the DSM which is more reliable than ICT as the DSM has been updated so inter-rather reliability of sz diagnosis has been improved
Rosenhan 2nd experiment
Informed hospitals of potential pseudo patients. Detected 193, were actually 0 admitted.
Concluded that sz diagnosis lacks validity bc clinicians cannot reliably diagnose and distinguish real and fake schizophrenics
Strength of culture bias
Rack: in many cultures it is normal to see, hear and interact with the dead e.g. Carribeans. Western cultures however see these traits as being schizophrenic. Therefore important to understand cultural context to have insight in how sz is diagnosed in different cultures
Limitation of culture bias
Low reliability
Cochrane: investigated sz in the West Indies and Britain and found they had similar levels of diagnosis. However, once they came to the Uk, they were 7 X more likely to be diagnosed with sz
Low test retest reliability
Limitation of symptom overlap
Leads to misdiagnosis which could lead to individuals not recieving the correct treatment
