Assessment issues

Question 1

What is evidence-based neuropsychology practice?

Answer 1

Providing care integrating clinical data, research literature, individual patient characteristics, financial realities, and cultural/social norms.

Question 2

What is flexible-battery approach?

Answer 2

Hypothesis-driven approach, systematic screening of all domains, more detailed assessment when deficits are identified

Question 3

What is process approach?

Answer 3

Focusing less on test scores and more on behavioral processes while obtaining that score

Question 4

What is normative comparison standard?

Answer 4

Species specific standard (e.g., language development) - lack is a pathognomonic sign (abnormal)
Population average - important to know whether distribution is normal or skewed
Does not provide sufficient information to identify a deficit within an individual, premorbid level of function is important

Question 5

What is individual comparison standard?

Answer 5

Comparison of scores relative to premorbid level of ability

Question 6

What is an example of ordinal data?

Answer 6

Likert scale data

Question 7

What is an example of interval level data?

Answer 7

T scores

Question 8

What is the difference between sensitivity and specificity?

Answer 8

High sensitivity rules out dx with a negative test result (sn-nout)
High specificity rules in a dx (sp-pin)

Question 9

What is positive/negative predictive value?

Answer 9

Likelihood that the person has the disease when the test is positive
Or negative when the condition is absent

Question 10

How is prevalence rate related to SN, SP, PPV, and NPV?

Answer 10

Prevalence rates affect PPV and PNV but not SN and SP

Decreased prevalence rate - decreased PPV

Question 11

What is post-test probability?

Answer 11

PPV for a positive test

1-NPV for a negative test

Question 12

What is the difference between pre-test probability and pre-test odds?

Answer 12

Pre-test probability = prevalence rate

Pre-test odds = prevalence/1 - prevalence

Question 13

What is LR+?

Answer 13

Likelihood ratio positive - estimate of how much a positive test result will change the odds of having the disease
Based on ratio of SN and SP

The more LR deviates from 1, the stronger the likelihood that the disease is present (LR >1)

Question 14

What is LR-?

Answer 14

LIkelihood ratio negative - change in odds of not having a disease when a test result is negative

The more LR deviates from 1, the stronger the likelihood that the disease is absent (LR < 0.01)

Question 15

What is the difference between odds ratio and likelihood ratio?

Answer 15

OR - measure of effect size, how harmful/beneficial an exposure is to an individual

LR - extent to which a particular test value increases the likelihood of disease being present or absent

Question 16

What is parametric statistical modeling?

Answer 16

Impairment defined relative to group

Based on extrapolation of the central limit theorem

Question 17

Bayesian statistical modeling

Answer 17

Impairment relative to an individual comparison standard

Using corrective variables to improve accuracy of prediction

Question 18

What are some cautions in interpreting scores as impaired?

Answer 18

Family-wise error rate - increasing likelihood of a positive test finding when multiple tests are administered

Lower IQ = more low scores
Higher IQ = more variability

Question 19

What is confirmatory bias?

Answer 19

Excluding contradictory test findings or history when it does not fit with a suspected disease or condition

Question 20

LR of a positive test compares

Answer 20

True positives to false positives

Question 21

LR of negative test compares

Answer 21

False negatives to true negatives

Question 22

LR of 1 indicates

Answer 22

That test result is just as likely in those with and without condition and the result does not add much relevant information

Question 23

What is the risk of focus on deficit measurement?

Answer 23

Underappreciating diversity and overattributing lo scores to brain injury/disease

Question 24

What are 5 principles for interpreting scores? (from Iverson in LBB)

Answer 24

1) low scores are relatively common across all test batteries
2) low scores depend on where you set your cutoff score
3) low scores vary by number of tests administered
4) low scores vary by demographic characteristics of examinee
5) low scores vary by level of intelligence

Question 25

What is the limitation of using normal curve in NP?

Answer 25

NC relates to a single score, while NP rely on multiple tests, which yield multiple scores.
E.g., a FP rate of at least one lost score will be considerably higher than that of a single test score

Question 26

What is the relationship between low scores and intelligence?

Answer 26

Patients with below average intelligence will have more low scores than those with above Ave I.

Among healthy older adults, 22-38% will have one or more scores below 5th %ile across a battery of memory tests; the number of low scores varies by intelligence

Question 27

What is the relationship between the length of battery and low scores?

Answer 27

The more tests given, the more likely a person to have >1 scores 1SD below the mean

Increasing number of tests will result in increased number of false positive for people with below ave I and increased rate of false negatives for people with above ave I

Question 28

What are some factors contributing to low scores?

Answer 28

Measurement error
Normative sample characteristics
Longstanding weaknesses
Situational: fluctuations in motivation, fatigue, inattentiveness, minor illness

Question 29

What is the relationship between SN, SP, and cutoff scores?

Answer 29

Higher cutoff - improve SN, reduce SP (more likely to correctly identify those with problems but also include those without)

Question 30

What are sex differences in NP to consider?

Answer 30

Women better on tasks of verbal learning and memory, verbal fluency, processing speed, and motor dexterity.

Men better on motor speed, some visual-spatial and visual-constructional tasks, arithmetic reasonign and computations.

Question 31

What is the key factor affecting test interpretation?

Answer 31

Sample characteristics, including size, non-normal distributions, skew, etc.

Question 32

What are factors that affect comparison of performance across tests?

Answer 32

Sample differences, measurement error, score magnitude, extreme scores, ceiling and floor effects, extrapolation/interpolation of scores