Level | Type of evidence |
---|---|
A | At least 2 consistent class I studies |
B | At least 1 class I study or 2 consistent class II studies |
C | At least 1 class II study or 2 consistent class III studies |
Expert consensus | Consensus among Canadian amyotrophic lateral sclerosis clinical experts where evidence meeting criteria for Level A through Level C is lacking |
* See Box 1 for definitions of study classes.