Dictionary of Evidence-based Medicine.pdf
Dictionary of Evidence-based Medicine.pdf
Dictionary of Evidence-based Medicine.pdf
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
<strong>Dictionary</strong> <strong>of</strong> <strong>Evidence</strong>-<strong>based</strong> <strong>Medicine</strong> 25<br />
is to construct a summary statistic for each cluster (school) and then<br />
analyse these summary values (Bland JM, Kerry SM (1997) Statistics notes.<br />
Trials randomised in clusters. BMJ. 315: 600. Kerry SM, Bland JM (1997)<br />
Analysis <strong>of</strong> a trial randomised in clusters. BMJ. 316: 54).<br />
Cluster sampling<br />
In cluster sampling members <strong>of</strong> the population to be sampled are first<br />
arranged into groups or clusters. The clusters are sampled and those<br />
selected are subsampled. Such cluster sampling is <strong>of</strong>ten multistaged. A<br />
recent study is illustrative. The investigators wanted to draw a sample <strong>of</strong><br />
12-17-year-olds from the Community Health Index (a listing <strong>of</strong> names and<br />
addresses <strong>of</strong> people registered with general practitioners within their<br />
health board). The sampling frame consisted <strong>of</strong> all postcode sectors. Thirty<br />
sectors were sampled. These sectors were stratified according to district<br />
and Carstairs score (a measure <strong>of</strong> affluence or deprivation within an area)<br />
and a sample <strong>of</strong> 40 people aged 12-17 years inclusive was drawn from each<br />
using a random procedure stratified by age and sex (Hughes K, McKintosh<br />
AM, Hastings G et al. (1997) Young people, alcohol and designer drinks:<br />
quantitative and qualitative study. BMJ. 314: 44-8).<br />
CMA (see Cost minimization analysis)<br />
Cochrane, Archie (1909-88)<br />
A visionary Scottish physician whose criticism <strong>of</strong> the medical pr<strong>of</strong>ession<br />
for not organizing 'a critical summary, by specialty or subspecialty, adapted<br />
periodically, <strong>of</strong> all relevant randomized trials' to guide practice acted as a<br />
catalyst for the establishment <strong>of</strong> the Cochrane Collaboration (see Cochrane<br />
A, Blythe M (1989) One man's medicine. An autobiography <strong>of</strong> Pr<strong>of</strong>essor Archie<br />
Cochrane. BMA, London).<br />
Cochrane Collaboration<br />
A collaborative network focusing on undertaking and making accessible<br />
systematic up-to-date reviews <strong>of</strong> randomized controlled trials <strong>of</strong> health<br />
care. The collaboration is named after Archie Cochrane, a Scottish physician.<br />
Initial funding was provided by the UK Department <strong>of</strong> Health to set<br />
up the UK Cochrane Centre but the collaboration is now international with<br />
a number <strong>of</strong> national and regional centres co-ordinating the work <strong>of</strong><br />
collaborative review groups and networks within their regions. The main