Why has ASCEND been going on for so long?
When the study started, it was originally planned that ASCEND participants would remain in the trial for an average of 5 years. This was based on calculations which anticipated that each year about 2 in every 100 people taking part might experience a heart attack or stroke. However, since the study began, on average many fewer (only about 1 in 100) people taking part in ASCEND have had heart attacks and strokes every year. Clearly this is good news for ASCEND participants but it also means that it is more difficult for the study to produce a reliable answer about whether the study treatments reduce that risk further, and whether any benefits of treatment outweigh the possible risks.
To answer these questions reliably it was necessary to extend the length of the study. In 2011, the Steering Committee, who are responsible for the running of ASCEND, decided to ask all participants to stay in the study for an average of 7½ years. This means that the study will go on until 2017. We appreciate that this is asking a lot of participants but ASCEND should be able to tell us whether aspirin and fish oils should be taken routinely or not. This result will be relevant to millions of people with diabetes around the world.