Randomised non-comparative trial
A randomised non-comparative trial, RNCT (or also non-comparative randomised trial[1]), is a type of clinical trial where participants are randomised to different conditions (arms), but where the primary analysis involves comparing each arm separately to a historical control, predefined benchmark or something else, with no formal comparison between the two arms.[2]
The study design appears to have arisen in oncology, where single-arm studies are not unusual. It promises reduced sample size requirements.[3] An RNCT acts like multiple single-arm designs run concurrently.[2] A review found RNCTs dating back to 2002, and having been used in high-profile oncology studies and also beyond oncology.[3]
The design has been criticised by statisticians. It is unclear what benefit randomisation adds compared to running separate single-arm studies.[3] Pavlos Msaouel described the use of the word "randomisation" as merely being "talismanic" in a 2025 article, it leading readers to think the study has the benefits of a randomised controlled trial (RCT).[2] While the point of an RNCT is not to have a comparison between arms, about half of reported RNCTs still reported some sort of comparison.[3]
References
[edit]- ↑ Sundar, Shyam; Pandey, Krishna; Mondal, Dinesh; Madhukar, Major; Kamal Topno, Roshan; Kumar, Ashish; Kumar, Vinod; Kumar Verma, Deepak; Chakravarty, Jaya; Chaubey, Rahul; Kumari, Poonam; Rashid, Md. Utba; Maruf, Shomik; Ghosh, Prakash; Raja, Sheeraz; Rode, Joelle; den Boer, Margriet; Das, Pradeep; Alvar, Jorge; Rijal, Suman; Alves, Fabiana (2024-06-20). "A phase II, non-comparative randomised trial of two treatments involving liposomal amphotericin B and miltefosine for post-kala-azar dermal leishmaniasis in India and Bangladesh". PLOS Neglected Tropical Diseases. 18 (6) e0012242. doi:10.1371/journal.pntd.0012242. ISSN 1935-2735. PMC 11189210. PMID 38900786.
- 1 2 3 Msaouel, Pavlos (2025-03-28). "The curious rise of randomised non-comparative trials". Significance. 22 (3): 40–44. doi:10.1093/jrssig/qmaf029. ISSN 1740-9705. Retrieved 2025-04-17.
- 1 2 3 4 Sherry, Alexander D.; Msaouel, Pavlos; Ludmir, Ethan B. (2024). "A meta-epidemiological analysis of post-hoc comparisons and primary endpoint interpretability among randomized noncomparative trials in clinical medicine". Journal of Clinical Epidemiology. 175 111540. doi:10.1016/j.jclinepi.2024.111540. Retrieved 2025-04-17.