Page 17 - 15Diarrhoeaandvomiting

Diarrhoea and vomiting caused by gastroenteritis in children under 5 years

Gastroenteritis A transient disorder due to enteric infection and characterised by the sudden
onset of diarrhoea with or without vomiting.
Generalisability The extent to which the results of a study hold true for a population of patients
beyond those who participated in the research. See also external validity.
Gold standard A method, procedure or measurement that is widely accepted as being the best
available, against which new developments should be compared.
Grey literature Reports that are unpublished or have limited distribution, and are not included
in easily accessible bibliographic retrieval system (such as journals or databases).
Guideline A systematically developed tool that describes aspects of a patient’s condition
and the care to be given. A good guideline makes recommendations about
treatment and care, based on the best research available rather than on opinion.
It is used to assist clinician and patient decision making about appropriate
health care for specific clinical conditions.
Guideline recommendation Course of action advised by the Guideline Development Group on the basis of
their assessment of the supporting evidence.
Health economics A branch of economics that studies decisions about the use and distribution of
healthcare resources.
Health technology Health technologies include medicines, medical devices such as artificial hip
joints, diagnostic techniques, surgical procedures, health promotion activities
(e.g. the role of diet versus medicines in disease management) and other
therapeutic interventions.
Health Technology The process of determining the clinical and cost-effectiveness of a health technol-
Appraisal (HTA) ogy undertaken by NICE to provide patients, healthcare professionals and man-
agers with an authoritative source of advice on new and existing health technologies.
Hepatosplenomegaly Abnormal enlargement of both the liver and the spleen.
Heterogeneity In the general sense, the term is used to describe variation in the participants,
interventions and outcomes across a set of studies. Statistical heterogeneity is
the term used in meta-analyses and systematic reviews to describe variation
in the results or estimates of effects beyond the amount expected solely due to
chance. It is the opposite of homogeneity.
Hierarchy of evidence An established hierarchy of study types, based on the degree of certainty that
can be attributed to the conclusions drawn from a well-conducted study. A
systematic review of good-quality randomised controlled trials (RCTs) with
homogeneity in their results (which are statistically significant) is at the top of
this hierarchy. Well-conducted studies of patients’ views and experiences would
appear at a lower level in the hierarchy of evidence.
Homogeneity In the general sense, the term is used to imply similarity in the participants,
interventions and outcomes across a set of studies. Statistical homogeneity
means that the results of studies or estimates of effects included in a systematic
review or meta-analysis are similar or they do not vary beyond the amount
expected by chance. It is the opposite of heterogeneity.
Hyperchloraemic acidosis An electrolyte and acid/base disturbance that may arise as a consequence of
infusing large quantities of chloride-containing solutions, such as 0.9% normal
saline.
Hyperglycaemia An abnormally high level of glucose in the bloodstream.
Hyperkalaemia An electrolyte disturbance in which the plasma potassium concentration is
greater than 5.5 mmol/l.
Hypernatraemia An electrolyte disturbance in which the plasma sodium concentration is greater
than 145 mmol/l. In severe hypernatraemia (e.g. plasma sodium levels more
than 160 mmol/l), there are risks associated with a sudden fall in plasma sodium
level during rehydration, and such patients require a modified approach to their
fluid management.
Hyperreflexia Overactive or overresponsive reflexes.
Hypertonicity Abnormally high muscle tension.
Hypoglycaemia An abnormally low level of glucose in the bloodstream.

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