Page 13 - 15Diarrhoeaandvomiting

Diarrhoea and vomiting caused by gastroenteritis in children under 5 years

Case–control study A type of observational study that compares a group of individuals with a particular
disease or outcome (known as cases) with a group of individuals without the
disease or outcome (known as controls). All subjects are then assessed with
respect to things that happened to them in the past to explore the association
between the disease/outcome and prior exposure to specific risk factors.
Case report (or case study) A type of observational study with detailed reports on one patient (or case),
usually covering the course of that person’s disease and their response to
treatment.
Case series A type of observational study with descriptions of several cases of a given disease,
usually covering the course of the disease and the response to treatment. There
is no comparison (control) group of patients.
Checklist See study checklist.
Clinical audit A systematic process for setting and monitoring standards of clinical care. Whereas
‘guidelines’ define what the best clinical practice should be, ‘audit’ investigates
whether best practice is being carried out. Clinical audit can be described as a
cycle or spiral. Within the cycle there are stages that follow a systematic process
of establishing best practice, measuring care against specific criteria, taking action
to improve care, and monitoring to sustain improvement. The spiral suggests that
as the process continues, each cycle aspires to a higher level of quality.
Clinical effectiveness The extent to which a specific treatment or intervention, when used under
usual or everyday conditions, has a beneficial effect on the course or outcome
of disease compared with no treatment or other routine care. (Clinical trials
that assess effectiveness are sometimes called management trials.) Clinical
‘effectiveness’ is not the same as efficacy.
Clinical importance The importance of a particular guideline recommendation to the clinical
management of the target population.
Clinical question A term sometimes used in guideline development work to refer to the questions
about treatment and care that are formulated in order to guide the search for
research evidence. When a clinical question is formulated in a precise way, it is
called a focused question.
Clinical trial A research study conducted to compare the effects of two or more healthcare
interventions, for example a trial conducted to assess the effectiveness and safety
of a new cancer drug compared with the old treatment. Each trial is designed
to answer scientific questions and find better ways to treat individuals with a
specific disease. This general term encompasses controlled clinical trials and
randomised controlled trials.
Clinician A healthcare professional providing patient care, for example doctor, nurse,
physiotherapist.
Cluster A group of patients, rather than an individual, used as the basic unit for
investigation. They might be families, schools, medical practices or whole
communities. See also cluster randomised trial.
Cluster randomised trial A trial in which groups of individuals or clusters (e.g. patients in a GP surgery or
people living in a community) are randomly allocated to treatment groups. It is
usually carried out to evaluate the effectiveness of an intervention provided at the
community level. Take, for example, a smoking cessation study of two different
interventions – leaflets and teaching sessions. Each GP surgery within the study
would be randomly allocated to administer one of the two interventions. See
also cluster.
Cochrane Collaboration An international, non-profit, independent organisation that maintains up-to-date
information about healthcare interventions by producing and disseminating
systematic reviews of their effectiveness. The Cochrane Database of Systematic
Reviews contains regularly updated reviews on a variety of health issues and is
available electronically as part of the Cochrane Library.
Cochrane Library A regularly updated collection of evidence-based medicine databases including
the Cochrane Database of Systematic Reviews (reviews of randomised
controlled trials prepared by the Cochrane Collaboration). The Cochrane Library
is available on CD-ROM and the internet.

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