What it means
Collecting more information about participants later in a study to see what has happened to them. The term can also mean the length of time researchers keep track of them.
Examples on this page are illustrations, not findings from the research cards.
Worked example
Researchers interview the same workers three months after a programme ends. That later interview is a follow-up.
Hypothetical example: researchers survey 100 volunteers when a project starts and contact them six months later. Eighty answer the later questionnaire. That is a six-month follow-up, with information missing for 20 of the original 100 volunteers.
Suppose volunteers with the lowest wellbeing are less likely to answer. Looking only at the 80 responses could make wellbeing appear higher than it is across all 100. The missing responses are a reason to investigate possible bias; their number alone does not establish its size or direction.
A closer look
Follow-up means collecting information about participants after an earlier point in a study. Researchers might contact them again, repeat a questionnaire or use records to find out what happened. Follow-up can take place while a programme is running or after it ends. The term can also describe the time covered: a six-month follow-up checks outcomes six months after a specified starting event.
Later measurements can show whether an early change continues, disappears or develops over time. Researchers also need to report who could be followed and whose information is missing. Missing responses do not automatically make findings biased. They can distort the picture when the reasons information is missing are related to the outcome being measured, so the respondents no longer fairly represent everyone the study needs to assess.
A common misunderstanding
Follow-up does not mean every original participant was measured again, or that missing responses automatically bias the findings.
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Sources
The wording and examples are original explanations informed by these references.
Cite this explanation
Follow-up. aikyam school. https://aikyam.school/glossary/follow-up/
Used in these cards
77 cards use this term
The original research wording is preserved in these cards.
