Single-arm trial
Single-arm trial
A trial with one investigational treatment group. An arm is a study group, not an individual participant.
How to read it
If 15 people receive the study regimen and changes from baseline are measured, it remains a single-arm study. Check for concurrent, historical or external comparators and whether populations are comparable.
A common pitfall
Improvement after treatment is not necessarily entirely caused by the drug; disease course, other treatments and measurement changes may contribute. Single-arm describes groups; open-label describes awareness of treatment.
Read it in context
How Far Must Medicine Go to Spare One More Operation? →Mylotarg: Why Did a Withdrawn Drug Return Seven Years Later? →Related concepts to distinguish
Arms describe groups; randomization describes assignment; masking describes who knows the treatment; endpoints describe what is measured.
Open-label study · Comparator · Randomized controlled trial · Primary endpoint