Report in English with a Dutch summary (KCE reports 45A)

12 Screening for Colorectal Cancer KCE reports vol.45
into a category other than that to which it should be assigned.
Morbidity Illness.
The number of deaths from a specified disease that are diagnosed or
Mortality rate
reported during a defined period of time in a given population.
Multiple Analysis of data that takes into account a number of variables
regression simultaneously.
Natural history The course of a disease from onset to resolution.
Negative The probability a person does not have the disease when the screening
predictive value test is negative.
The number of patients who would need to be screened, for a given
period of time, in order to prevent a single event (i.e. death from
Number needed colorectal cancer). The smaller the NNS, the fewer people need to be
to Screen screened to prevent an event. The NNS often varies markedly with
risk factors such as age and in general with incidence of the disease in
that population.
The number of patients who must be exposed to an intervention
Number Needed
before the clinical outcome of interest occurs; for example, the
to Treat
number of patients needed to treat to prevent one adverse outcome.
A proportion in which the numerator contains the number of times an
Odds
event occurs and the denominator includes the number of times the
event does not occur.
Odds ratio A measure of the degree or strength of an association. In a case
Cross-product control or a cross-sectional study, it is measured as the ratio of the
ratio
odds of exposure (or disease) among the cases to that among the
Relative odds controls.
The key feature that distinguishes opportunistic screening from
screening programs is the lack of a quality process, including routine
monitoring and evaluation. Opportunistic screening usually occurs
when a person who is presenting to the health system for another
Opportunistic
reason is asked a question or offered a test in order to detect the
screening
presence or confirm the absence of a specific condition. Opportunistic
screening may be organised to a greater or lesser degree. However,
because there are no attendant quality processes, its safety,
effectiveness and costeffectiveness cannot be assessed and guaranteed.
A person who goes to a health care facility for a consultation, and who
Outpatient leaves the facility within three hours of the start of the consultation. An
outpatient is not formally admitted to the facility.
A population-based screening program is one in which screening is
Population based
systematically offered by invitation to a defined, identifiable population;
screening
this requires a means of identifying and inviting the target population,
program
for example through a population register.
Population screening programs involve screening entire populations or
a large and easily identifiable group within a population. The target
Population
population group for screening may be defined geographically or by
screening
some other characteristics such as gender, age or ethnicity. The New
programs
Zealand cervical and breast screening program are examples of
population screening programs.
Positive
The probability that a person actually has the disease when the
predictive value screening test is positive.
Power The ability of a study to demonstrate an association if one exists.
The range in which the best estimates of a true value approximate the
Precision
true value.
In screening and diagnostic tests, the probability that a person with a
Predictive value
positive test is a true positive (i.e., does have the disease), or that a