Canada

The article includes the following highlights:

[O]nly three per cent of Canadian human research trials testing new drug treatments or therapies meet all three international criteria that ensure fair and timely sharing of results for all to learn from. Its authors say the look at whether these trials are properly registered, with results reported and formally published, serves as a clear warning that researchers may be wasting millions of dollars of funding, along with patients’ time and effort.

"Our data shows that there's basically no public record of many trial results... I think it's (scary) really," said Kelly Cobey, a co-author of the study, associate professor at the University of Ottawa and researcher at the university's Heart Institute.

[…]

The question posed by the research team was to determine how many followed the World Health Organization guidelines from 2015, which specify that: clinical trials must be registered before they begin to ensure they follow a pre-planned design; that key findings are made publicly available within a year of the study’s completion; and that the results are published in a journal at most two years after completion, "regardless of the outcome."

Of the Canadian trials studied, however:

• only 59 per cent were registered before enrolling participants to ensure a public record of ongoing trials;
• 32 per cent (2,138 studies) never reported their results, nor published their findings, according to the study; and
• only 3 per cent (123 studies) met all three criteria.