Glossary

Absolute Risk Reduction (ARR) is the difference in the event rate between control group (CER) and treated group (EER): ARR = CER - EER.

Case-control Study involves identifying patients who have the outcome of interest (cases) and control patients without the same outcome, and looking back to see if they had the exposure of interest.

Case-series is a report on a series of patients with an outcome of interest. No control group is involved.

Control Event Rate(CER) : see Event Rate below.

Clinical Practice Guideline is a systematically developed statement designed to assist practitioner and patient make decisions about appropriate health care for specific clinical circumstances.

Cohort Study involves identification of two groups (cohorts) of patients, one which did receive the exposure of interest, and one which did not, and following these cohorts forward for the outcome of interest.

Cost-Effectiveness Analysis converts effects into health terms and describes the costs for some additional health gain (e.g. cost per additional MI prevented).

Crossover Study Design: the administration of two or more experimental therapies one after the other in a specified or random order to the same group of patients.

Cross-Sectional Study the observation of a defined population at a single point in time or time interval. Exposure and outcome are determined simultaneously. Decision Analysis is the application of explicit, quantitative methods to analyse decisions under conditions of uncertainty.

Experimental Event Rate(EER) : see Event Rate below.

Event Rate is the proportion of patients in a group in whom an the event is observed. Thus, if out of 100 patients, the event is observed in 27, the event rate is 0.27. Control Event Rate (CER) and Experiemental Event Rate (EER) are used to refer to this in control and experimental groups of patients respectively.

Evidence-Based Health Care extends the application of the principles of Evidence-Based Medicine (see below) to all professions associated with health care, including purchasing and management.

Evidence-Based Medicine is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence-based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.