I dont understand how if you apply any logic you can come to the conclusion that accidents are more likely to happen in roundabouts than normal cross section.
You have to rely that drivers won't go into the roundabout before it's their turn and that drivers in the roundabout don't turn at the last minute or make other mistakes. In a single land roundabout it's not a big deal but when you get more than one lane then yes it does seem really easy for accidents to happen. Look at this