In fact, 44 percent of people starting dialysis has kidney failure caused by diabetes.
or

In fact, 44 percent of people starting dialysis have kidney failure caused by diabetes.

If you said,"Each of them", then you would use ,"Has"
However, 44% of people, [with people in plural] would be, "Have"
It doesn't matter wether it is 44% or 1% of people.
Hope this helps.
Lyn