Page 23 - 15Diarrhoeaandvomiting

Diarrhoea and vomiting caused by gastroenteritis in children under 5 years

Reliability Reliability refers to a method of measurement that consistently gives the same
results. For example, someone who has a high score on one occasion tends to
have a high score if measured on another occasion very soon afterwards. With
physical assessments it is possible for different clinicians to make independent
assessments in quick succession, and if their assessments tend to agree then the
method of assessment is said to be reliable.
Retrospective study A retrospective study deals with events or outcomes that have already occurred
in the past and does not involve studying future events. This contrasts with
studies that are prospective.
Risk See absoute risk or risk.
Risk difference (RD) The absolute difference between the risks of two groups. Also known as absolute
risk difference.
Royal Colleges In the UK medical/nursing world the term ‘royal colleges’, as for example in ‘The
Royal College of …’, refers to organisations that usually combine an educational
standards and examination role with the promotion of professional standards.
Safety netting The provision of support for patients in whom the clinician has some uncertainty
as to whether the patient has a self-limiting illness and is concerned that their
condition may deteriorate. Safety netting may take a number of forms, such
as dialogue with the patient or carer about symptoms and signs to watch for,
advice about when to seek further medical attention, review after a set period,
and liaising with other healthcare services.
Sample A part of the study’s target population from which the subjects of the study
will be recruited. If subjects are drawn in an unbiased way from a particular
population, the results can be generalised from the sample to the population as
a whole.
Scottish Intercollegiate SIGN was established in 1993 to sponsor and support the development of evidence-
Guidelines Network (SIGN) based clinical guidelines for the NHS in Scotland.
Secondary care Care provided in hospitals.
Secondary outcome An outcome deemed a priori as less important than the primary outcome and is
measured to evaluate additional effects of the intervention.
Selection bias A type of bias that occurs if:
• the characteristics of the sample differ from those of the wider population from
which the sample has been drawn, or
• there are systematic differences between comparison groups in a study in
terms of prognosis or responsiveness to treatment.
Selection criteria Explicit standards used by guideline development groups to decide which studies
should be included and excluded from consideration as potential sources of
evidence.
Semi-structured interview Structured interviews involve asking people pre-set questions. A semi-structured
interview allows more flexibility than a structured interview. The interviewer asks
a number of open-ended questions, following up areas of interest in response to
the information given by the respondent.
Sensitivity In diagnostic testing, this refers to the proportion of cases with the target
condition correctly identified by the diagnostic test out of all the cases that have
the target condition.
Shock A pathological condition in which there is inadequate blood perfusion of the
vital organs.
Single-blind study A study in which either the subject (patient/participant) or the observer (clinician/
investigator) is not aware of which treatment or intervention the subject is
receiving.
Skin turgor A term used to describe a physical characteristic of the skin. In patients with
clinical dehydration, skin turgor may be reduced, so that when a fold of skin is
gently pinched and then released it fails to immediately retract in the normal
way, but rather retains a ridged appearance for a variable period owing to a
reduction in its fluid content.

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