Discontinuation and non-publication of surgical randomised controlled trials: observational study: Senior and corresponding author

Research output: Contribution to conference (unpublished)Paperpeer-review


Objective To determine the rate of early discontinuation and
non-publication of randomised controlled trials involving patients
undergoing surgery.
Design Cross sectional observational study of registered and published
Setting Randomised controlled trials of interventions in patients
undergoing a surgical procedure.
Data sources The ClinicalTrials.gov database was searched for
interventional trials registered between January 2008 and December
2009 using the keyword “surgery”. Recruitment status was extracted
from the ClinicalTrials.gov database. A systematic search for studies
published in peer reviewed journals was performed; if they were not
found, results posted on the ClinicalTrials.gov results database were
sought. Email queries were sent to trial investigators of discontinued
and unpublished completed trials if no reason for the respective status
was disclosed.
Main outcome measures Trial discontinuation before completion and
non-publication after completion. Logistic regression was used to
determine the effect of funding source on publication status, with
adjustment for intervention type and trial size.
Results Of 818 registered trials found using the keyword “surgery”, 395
met the inclusion criteria. Of these, 21% (81/395) were discontinued
early, most commonly owing to poor recruitment (44%, 36/81). The
remaining 314 (79%) trials proceeded to completion, with a publication
rate of 66% (208/314) at a median time of 4.9 (interquartile range 4.0-6.0)
years from study completion to publication search. A further 6% (20/314)
of studies presented results on ClinicalTrials.gov without a corresponding
peer reviewed publication. Industry funding did not affect the rate of
discontinuation (adjusted odds ratio 0.91, 95% confidence interval 0.54
to 1.55) but was associated with a lower odds of publication for completed
trials (0.43, 0.26 to 0.72). Investigators’ email addresses for trials with
an uncertain fate were identified for 71.4% (10/14) of discontinued trials
and 83% (101/122) of unpublished studies. Only 43% (6/14) and 20%
(25/122) replies were received. Email responses for completed trials
indicated 11 trials in press, five published studies (four in non-indexed
peer reviewed journals), and nine trials remaining unpublished.
Conclusions One in five surgical randomised controlled trials are
discontinued early, one in three completed trials remain unpublished,
and investigators of unpublished studies are frequently not contactable.
This represents a waste of research resources and raises ethical
concerns regarding hidden clinical data and futile participation by patients
with its attendant risks. To promote future efficiency and transparency,
changes are proposed to research governance frameworks to overcome
these concerns.
Original languageEnglish
Publication statusPublished - 9 Dec 2014


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