Most US trials are too ‘small, poorly designed’

Data was analysed from 96,000 interventional trials registered at between 2007 and 2010.

Studies were dominated by small, single-centre trials, the researchers found. More than 96% had anticipated enrolment of 1000 or fewer participants and 62% had 100 or fewer participants.

Many trials had weaknesses in design and methodological approaches and significant heterogeneity, including in size, making it hard to compare them.

Looking at major areas of research they found that cardiovascular trials tended to be twice as large as oncology trials.

Some 47% were not funded by industry or