Do trialists endorse clinical trial registration? Survey of a Pubmed sample

Despite intense interest in trial registration, there is a wide gap between theoretical postulates on trial registration and its implementation worldwide.

We aimed to evaluate trialists views about current international guidelines on trial registration, including the World Health Organization's (WHO) International Clinical Trials Registry Platform (ICTRP) policies and the Ottawa Statement, as well as their intention to register any future clinical trials they conduct.

We identified all 40,158 PUBMED-indexed clinical trials published from May 2005 to May 2006 using an advanced search strategy. From a random sample of 500 confirmed clinical trials, corresponding authors with e-mail contact addresses were surveyed.

A total of 275 (60%) questionnaires from 45 countries were completed. 31% of the respondents had received only nonindustry funding during the past ten years, while 5% and 61% had received only industry or mixed funding respectively. Approximately two third of participants supported registration of all 20 WHO Data Set items, and endorsed the Ottawa Statement part 1 and part 2. Delayed public disclosure of some essential data in instances where they may be considered sensitive for competitive commercial reasons was supported by 30% of the participants, whereas immediate disclosure was supported by 53%. Only 21% of participants had registered all of their ongoing trials since 2005, while 47% stated that they would provide the 20 WHO Data Set items to a publicly accessible register for all their future clinical trials; a significantly higher proportion of participants who received only nonindustry funding (62%) was found among those who would always provide the 20 WHO items for future trials, compared to 42% of participants who received mixed or only industry funding. Among those who were undecided about endorsing registration. One third of participants expressed a lack of sufficient knowledge as the primary reason.

Although disagreement was apparent on certain issues, our findings illustrate that trial registration is gradually becoming part of the current research paradigm internationally. Our results also suggest that researchers require more knowledge to inform their decision to comply with the International standards at this early stage of voluntary trial registration.