Table 1.

Proposed scales and scores for assessing the three components of pertinence of study relevant to small randomised controlled trial under design

Cancer	Treatment	Endpoint	Component score
Same disease and stage	Same as proposed standard and experimental treatments	Overall survival	1
Same disease, different stage or type of patient	Same standard treatment, similar experimental treatment (eg different dose)	PFS, DFS, or EFS; adjustment factor available	0.9
Different site, same biology/histology	Similar standard and experimental treatments	PFS, DFS, or EFS; adjustment factor unavailable	0.8
Same site, different biology/histology		Response rate validated as a surrogate endpoint	0.5
Different site, some similarity	Some similarity in standard or experimental treatment, or both	Response rate not validated as surrogate end point	0.3
Different disease	Unrelated treatments	Unrelated end points	0

DFS=disease-free survival, PFS=progression-free survival, EFS=event-free survival.