Concepts Journal Club 1

Question 1

Incidence

Answer 1

The number of new occurrences of a condition (or disease) in a population over a period of time.

Question 2

Prevalence

Answer 2

The measure of a condition in a population at a given point in time (number of existing cases / population at risk).

Question 3

Rationale

Answer 3

A set of reasons or a logical basis for a course of action or belief.

Question 4

Hypothesis

Answer 4

An idea or explanation for somethin that is based on known facts but has not yet been proved.

Question 5

Research question

Answer 5

The fundamental core of a research project, study, or review of literature. It focuses on the study, determines the methodology, and guides all stages of inquiry, analysis and reporting.

Question 6

Objective (aim)

Answer 6

Emphasizes what needs to be achieved within the scope of the research, by the end of the research process. It is the eventual goal.

Question 7

Cohort

Answer 7

A study design where one or more samples (called cohorts) are followed prospectively and subsequent status evaluations with respect to a disease or outcome are conducted to determine which initial participants exposure characteristics (risk factors) are associated with it. As the study is conducted, outcome from participants in each cohort is measured and relationships with specific characterstics determined.

Question 8

Sample

Answer 8

Set of data collected and/or selected from a statistical population by a defined procedure. A sample can also show what the whole is like of a population.

Question 9

Modifiable risk factor

Answer 9

Risk factors are conditions that increase your risk of developing a disease. Risk factors can be modifiable, meaning you can take measures to change them, or non-modifiable, which means they cannot be changed.

Question 10

Mortality risk / rate

Answer 10

A measure of the number of deaths ( in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time.

Question 11

Reference and index test

Answer 11

Test of accuracy that is evaluated against the reference standard. It is the best available method of categorizing participants in a study of diagnostic test accuracy as having or not having a target condition.

Question 12

Gold standard method

Answer 12

The test that always gives a hit (true positive) when the disease is there and never give a hit when there is no disease (true negative).

Question 13

Single site

Answer 13

A single location or a group of contiguous locations.

Question 14

Reliability (of study / of measure)

Answer 14

This refers to how consistently a method measures something. If the same results can be consistently achieved by using the same methods under the same circumstances, the measurement is considered reliable.

Question 15

Accuracy

Answer 15

The deviation of a measurement from the true value.

Question 16

Reproducibility

Answer 16

The ability of a researcher to get exactly the same results of a prior study, using the same materials that were used by the previous researcher. It requires a sharing of several data sets depending on the type of research. The meaning of reproducibility lies within issues of trust to show the data and analyses are as presented and do not state that the findings are acceptable.

Question 17

Precision

Answer 17

How close a group of measurements are together.

Question 18

Validity (of study / of measure)

Answer 18

How accurately a method measures what it is intended to measure. If research has high validity, that means it produces results that correspond to real properties, characteristics, and variations in the physical/social world.

Question 19

Sensitivity

Answer 19

It refers to a tests ability to designate an individual with the disease as positive. A highly sensitive test means there are few false negative results, and thus fewer cases of the disease are missed.

Question 20

Specificity

Answer 20

Specificity of a test is its ability to designate an individual who does not have a disease as negative.

Question 21

Variation / Variability

Answer 21

Variance is the expectation of a random variable from its mean of the squared deviation. Variability is the extent to which the data points vary from the average value in a data set or statistical distribution.

Question 22

Daily repeat analysis

Answer 22

Repeat or retake analysis is an essential aspect of quality management program. It is an organized process of categorizing rejected images and finding out the nature of the repeated images to minimize or eliminate them in the future.

Question 23

Coefficient of variation

Answer 23

This is used in analytical chemistry to calculate repeatability and precision of research procedure in which the standard deviation is again involved, to be more precisely the CV is expressed as the ratio of the standard deviation. Thus it is another way the measure variability.

Question 24

95% confidence interval

Answer 24

The confidence interval states that when an infinite number of experiments were to be done, 95% would fall in between these intervals. Infinite number is not possible, but the assumption of such a confidence interval can be made if the experiment meets certain criteria such as a large enough sample size which would represent a population.

Question 25

Median difference

Answer 25

The median is the value of the observation for which half the observations are larger and half are smaller. If there are an even number of data points, the mean is taken from the two middle points.

Question 26

Median, Interquartile range

Answer 26

The IQR describes the middle 50% of values when ordered from lowest to highest.

Question 27

Bias

Answer 27

Supporting or opposing a certain statement or person based on emotional aspects.

Question 28

Funding and support

Answer 28

Definitions of financial support to make some projects possible.

Question 29

Competing interests / Conflict of interests

Answer 29

A competing interest - often called a conflict of interest - exists when professional judgement concerning a primary interest (e.g. patients welfare) may be influenced by a secondary interest (e.g. personal rivalry).