Given the reality of the business world, it's sometimes necessary to hire someone because you need a "warm body". You have to accept that fact. But you don't have to accept that it's inevitable that it's "just the cost of doing business".
By predicting the performance of your caregiver candidates you'll cut down on your caregiver turnover simply by ONLY hiring people that have what it takes to be good at the job. And as you've probably learned over the years, looking at past experience really can't tell you if the candidate is any good at the job.