- confidence interval - An interval describing the range of values within which there is reasonable certainty that the true effect lies. Uncertainty increases with the width of the interval.
- mean difference - the absolute difference between the mean value in two groups in a clinical trial, which estimates the amount by which the intervention changes the outcome on average compared with the control.
- odds ratio - the ratio of the likelihood of an event occurring in one group to that of it occurring in another group. An odds ratio of 1 indicates that the condition or event under study is equally likely to occur in both groups. An odds ratio greater than 1 indicates that the condition or event is more likely to occur in the rst group and an odds ratio less than 1 indicates that the condition or event is less likely to occur in the first group.
- outcome reporting bias - the selective reporting of some outcomes but not others. Outcomes with favourable ndings may be reported more. For example, adverse events have been found to be reported more often in unpublished studies. This may result in more favourable results for published studies.
- randomised controlled trial - a study in which participants are allocated at random to receive one of several clinical interventions. One of these interventions is the standard of comparison or control. The control may be a standard practice, a placebo or no intervention at all.
- relative risk - the ratio of the risk (rate) of an outcome in an exposed group (eg to a speci c medicine) to the
risk (rate) of the outcome in an unexposed group in a speci ed time period
- sensitivity - the proportion of people with the condition who have a positive test result.