Further research is necessary
As was the association between both progression-free survival and overall survival rates. In fact, the patient taking a PIM was a strong independent predictor of whether or not the patient was going to survive.
The study did not delve into how and why PIMs are potentially dangerous for elderly patients, but it did show that the reduction in survival rate is not just an anecdote. However, the data is still correlative instead of causal, which means that it also does not show that PIMs cause the reduction in survival rate. It just links the two. Further research will be necessary.