Available case analysis	Analysis that includes data on only those whose results are known, using as a denominator the total number of people who had data recorded for the particular outcome in question (Higgins 2011c).
Funnel plot	Simple scatter plot of the intervention effect estimates from individual studies against some measure of each study’s size or precision (Sterne 2011).
Intention‐to‐treat analysis	Analysis that fulfils the next principles: 1) keeps participants in the intervention groups to which they were randomised, regardless of the intervention they actually received; 2) there is a measurement of outcome data on all participants; and 3) includes all randomised participants in the analysis (Higgins 2011c).
Quasi‐randomised controlled clinical trial (Q‐RCT)	Type of study where the participants (or groups of participants) are assigned prospectively to an intervention or to a control group (or more) using a process that attempts but does not achieve true randomisation (for example, alternation of allocation, birth dates or week days).
Small‐study effects	A tendency for estimates of the intervention effect to be more beneficial in smaller studies (Sterne 2011).