Table 6.

Key points from ASCEND trial

Trial name (registration)	ASCEND: A Study of Cardiovascular Events iN Diabetes19 20 (NCT00135226)
Sponsorship	Academic – Oxford.
Clinical setting	Diabetes mellitus, UK only: national, mail-based methods – no study sites.
Design	2×2 factorial design randomised placebo-controlled trial (phase 4).
Size	n=15 000.
Key outcome measure	Cardiovascular events.
Rationale for presentation	Recruitment, conduct and follow-up.
Key discussion points	ASCEND used highly streamlined mail-based methods to identify, recruit and follow-up (for an average of 7.5 years) 15 500 UK patients, making it one of the longest duration and largest ever trials in diabetes. Participants completed 6-monthly follow-up questionnaires, initially using paper, but later moving to an online system for those who wished. The trialists gained access to HES data during the closing stages of the study, allowing additional follow-up information to be gained for those who had not returned a recent questionnaire. Subsequent analyses of the HES data compared with questionnaire data showed good concordance, suggesting that, in the UK, HES data alone could be used as a highly efficient means of follow-up for cardiovascular trials in the future.

HES, Hospital Episode Statistics.