I have found a report that mentions incorrect classification of COPD patients by relying on the 70% and 80% ratios / value, it states to use the LLN instead.
Would someone be kind enough to explain to me what the 5th percentile means? I think I know but would like expert clarification.
I suppose a lot plays into this, like history and symptoms. Its my opinion that some Medics still rely on clinical evidence only, especially when choosing to not to diagnose mild disease. It also seems diagnostic criteria change often in line with new information.