Table 3.

Recommended levels for plasma exchange (2, 29).

Recommendation	Grade 1A	Grade 1B	Grade 1C	Grade 2A	Grade 2B	Grade 2C
The quality of evidence	RCT without significant limitation or overwhelming evidence from observational studies.	RCT has important limitations (inconsistent results, methodological defects) or exceptionally strong evidence from observational studies.	Case series or observational studies.	RCT without significant limitation or overwhelming evidence from observational studies.	RCT has important limitations (inconsistent results, methodological defects) or exceptionally strong evidence from observational studies.	Case series or observational studies.
Detailed description	Strong recommendation, high-quality evidence.	Strong recommendation, moderate-quality evidence.	Strong recommendation, low-quality, or very low-quality evidence.	Weak recommendation, high-quality evidence.	Weak recommendation, moderate-quality evidence.	Weak recommendation, low-quality, or very low-quality evidence.