A review of current practice in the design and assessment of internal pilots in UK NIHR clinical trials

Table 1 Details of the design of the internal pilots

	Frequency (%)
Data sources
Commissioning briefs	28^a (100%)
Project descriptions	41 (72%)
Summary of changes from first stage/feedback about full application	41 (72%)
Monitoring notes	56 (98%)
Progress report history	56 (98%)
Protocols (current version available online)	57 (100%)
Protocols (any previous versions available online)	37 (65%)
Where was the internal pilot first proposed?
	Funder-led	Researcher-led
Commissioning brief	8 (29%)	N/A
Outline	6 (27%)	14 (64%)
Outline feedback	6^b (27%)	7^c (32%)
Full application	0 (0%)	0 (0%)
Full application feedback	2 (9%)	1 (5%)
Total	22^d (100%)	22^d (100%)
Trials with progression criteria specified in the latest available version of the protocol
Yes	36 (63%)
No	21 (37%)
If yes, specified in previous available versions?
Yes	19 (86%)
No	3 (14%)
Previous versions not available	14
Component(s) of progression criteria^e
Target number for recruitment within a specified period	54 (96%)
In a specified number of sites?
Yes	4 (7%)
No	50 (93%)
Retention/primary outcome ascertainment rate	16 (29%)
Rate of treatment adherence	13 (23%)
Rate of randomisation over time	11 (20%)
Rate of randomisation by site?
Yes	8 (73%)
No	3 (27%)
Number of sites recruiting	10 (18%)
Consent rate	8 (14%)
Number of sites opened	5 (9%)
Proportion of eligible participants	3 (5%)
Other^f	4 (7%)

^aDenominator 28 as only applicable for the 28 funder-led trials
^bThe outline feedback suggested amendments to an additional 6 internal pilots, 4 of which were initially proposed in the commissioning brief and 2 which were proposed in the outline
^cThe outline feedback suggested amendments to an additional 8 internal pilots, all of which were initially proposed in the outline
^d5 unknown for funder-led trials; 8 unknown for researcher-led trials; commissioning brief denominator = 28
^eCriteria was not specified for 1 internal pilot so denominator taken as 56
^fNumber of UK participants; number receiving rescue treatments; outcome assessments conducted according to protocol; number of sites that completed the intervention course

ISSN: 1745-6215