STRATEGIES IN EPIDEMIOLOGY: Measurements and Measurement Errors; Assessing Evidence of Disease Causation

Question 1

A number or label assigned to empirical properties of a variable according to rules

Answer 1

MEASUREMENT

Question 2

numerals that have quantitative meaning

Answer 2

NUMBERS

Question 3

attributes that have qualitative meaning

Answer 3

LABELS

Question 4

Categorizing each subject into 2 or more mutually exclusive groupS

Answer 4

CLASSIFICATION (LABELS)

Question 5

examples of CLASSIFICATION (LABELS)

Answer 5

• NUTRITIONAL STATUS
• SEVERITY OF PAIN
• DISEASE STATUS

Question 6

The fewer / smaller the errors, the better the measurements

Answer 6

QUALITY OF MEASUREMENTS

Question 7

errors of QUALITY OF MEASUREMENTS

Answer 7

• MISSCLASSIFICATION
• DEVIATION

Question 8

Pre-requisite for making measurements

Answer 8

OPERATIONAL DEFINITION

Question 9

example of OPERATIONAL DEFINITION

Answer 9

• WEIGHT

Question 10

[OPERATIONAL DEFINITION]

measurement of gravitational force acting on an object

Answer 10

CONTEXTUAL

Question 11

[OPERATIONAL DEFINITION]

result of an object on a Newton spring scale

Answer 11

OPERATIONAL

Question 12

give the FOUR ‘SOURCES OF ERROR’

Answer 12

1. OBSERVER: examiner, interviewer
2. SYSTEM: coding and classifying systems
3. SUBJECTS
4. INSTRUMENT

Question 13

[SOURCES OF ERROR]

• Differences or changes in the diagnostic criteria used by most clinicians
• Differences or changes in the application of diagnostic criteria by individual clinicians
• Prior knowledge

Answer 13

OBSERVER: examiner, interviewer

Question 14

[SOURCES OF ERROR]

• Defects or changes in Classification of diseases / causes of death Coding of diseases / causes of death

Answer 14

SYSTEM: coding and classifying systems

Question 15

[SOURCES OF ERROR]

• Behavioral
• Interactive responses
• Biologic variability

Answer 15

SUBJECTS

Question 16

[SOURCES OF ERROR]

‘SUBJECTS’

• Recall problems
• Unwillingness to disclose information

Answer 16

BEHAVIORAL

Question 17

[SOURCES OF ERROR]

‘SUBJECTS’

• Response modified by the behavior of interviewer
• Response modified by knowledge that one is being observed or studies

Answer 17

INTERACTIVE RESPONSES

Question 18

[SOURCES OF ERROR]

‘SUBJECTS’

• Random or short-term fluctuations in some biological factors

Answer 18

BIOLOGIC VARIABILITY

Question 19

[SOURCES OF ERROR]

• Equipment / mechanical instrument
• Single index instrument
• Abstraction form
• Observation Checklist

Answer 19

INSTRUMENT

Question 20

[SOURCES OF ERROR]

‘INSTRUMENT’

• Analytic or scaling problems of combining information from 2 or more items to form an overall index or indicator of the factor/disease

Answer 20

SINGLE INDEX INSTRUMENT

Question 21

[SOURCES OF ERROR]

‘INSTRUMENT’

• not properly labeled
• incomplete / unclear

Answer 21

ABSTRACTION FORM

Question 22

[SOURCES OF ERROR]

‘INSTRUMENT’

• incomplete / unclear

Answer 22

OBSERVATION CHECKLIST

Question 23

[ABSTRACT and CONCRETE VARIABLES]

• not measured directly
• not easily defined
• measured by combining the results of 2 or more item scores into single index

Answer 23

ABSTRACT

Question 24

[ABSTRACT and CONCRETE VARIABLES]

• measured directly
• easily defined
• closely related to observed variables

Answer 24

CONCRETE

Question 25

examples of INDICATORS OF A VARIBALES

Answer 25

- Single - Composite - Proxy indicator

Question 26

[INDICATORS OF A VARIBALES] - obvious and has one indicator

Answer 26

SINGLE

Question 27

[INDICATORS OF A VARIBALES] - not so obvious and can have multiple indicators

Answer 27

COMPOSITE

Question 28

human errors which involves PROCESSING, DATA ABSTRACTION, TRANSCRIPTION, IMPROPER USE OF SOFTWARE, SOFTWARE VIRUSES/BUGS

Answer 28

DATA PROCESSING

Question 29

two examples of CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT

Answer 29

- RELIABILITY - VALIDITY

Question 30

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] 'RELIABILITY' examples

Answer 30

- INTER-OBSERVER RELIABILITY - INTRA-OBSERVER RELIABILITY - INTERNAL CONSISTENCY

Question 31

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] 'VALIDITY' examples

Answer 31

- SENSITIVITY - SPECIFICITY - PREDICTIVE VALUE (+) - PREDICTIVE VALUE (-)

Question 32

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] - the extent to which the measurements obtained are reproducible or repeatable

Answer 32

RELIABILITY

Question 33

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] 'RELIABILTY' - Across 2 or more observer

Answer 33

INTER-OBSERVER RELIABILITY

Question 34

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] 'RELIABILITY' - Within the same person looking at the same data, giving same results

Answer 34

INTRA-OBSERVER RELIABILITY

Question 35

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] 'RELIABILITY' - Similarity among items of a composite measure

Answer 35

INTERNAL CONSISTENCY

Question 36

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] - the extent to which measurements reflect the true values of the theoretical factors that the observed variable is supposed to measure

Answer 36

VALIDITY

Question 37

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] 'VALIDITY' - proportion of people labelled positive by the test among those with the disease

Answer 37

SENSITIVITY

Question 38

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] 'VALIDITY' - proportion of people labelled negative by the test among those without the disease

Answer 38

SPECIFICITY

Question 39

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] 'VALIDITY' - proportion of people who tested positive who have the disease

Answer 39

PREDICTIVE VALUE (+)

Question 40

[CRITERIA FOR ASSESSING QUALITY OF MEASUREMENT] 'VALIDITY' - proportion of people who tested negative among those without the disease

Answer 40

PREDICTIVE VALUE (-)