The CDC that shows that "several studies have shown that out of 2,500 cases of bedsores in patients treated with Murphy beds, 20 percent resulted in death." That's only 20% but then they don't mention how many patients there were or how many deaths occurred.
Therefore, it is impossible to know if the claim is true or false without more information from the study cited above. We also don't know if all the injuries related to these beds were fatal or if they occurred at such a low rate that they didn't make it into any statistical analysis.