LTFU
Medical abbreviation · Medical Research
| Stands for | Lost to follow-up |
|---|---|
| Categories | Medical |
LTFU stands for Lost to follow-up, a medical research abbreviation.
Participants whose outcomes become unknown because they stop attending visits or cannot be contacted before a study ends. High or unequal rates of loss to follow-up can bias results, since those lost often differ from those who remain.
Example: LTFU was 18% in the control arm versus 6% in the treatment arm.
Usage notes
A common rule of thumb treats losses under about 5 percent as minor and over 20 percent as a serious threat to validity. Sensitivity analyses test how different assumptions about missing outcomes change conclusions. Collecting several contacts per participant and linking to death registries reduce losses.
Related abbreviations
More medical research abbreviations
- IQR – Interquartile range
- IRB – Institutional review board
- ITT – Intention-to-treat
- KM – Kaplan-Meier (estimator)
- LOE – Level of evidence
- LR – Likelihood ratio
- MA – Meta-analysis
- MedDRA – Medical Dictionary for Regulatory Activities
- MeSH – Medical Subject Headings
- MHRA – Medicines and Healthcare products Regulatory Agency
- NCT – National Clinical Trial (number)
- NICE – National Institute for Health and Care Excellence
See all 94 medical research abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.