Table 1.

SAVES-V2 severity grades.

Severity of AE	Clinical Impact
1	AE does not require treatment & has no adverse effect
2	AE requires minor invasive (e.g., Foley catheter, nasogastric tube) or simple treatment but has no long-term effect
3	AE requires invasive (e.g., surgery) or complex treatment (e.g., monitored bed) & is most likely to have a temporary (<6 months) adverse effect on outcome
4	AE requires invasive (e.g., surgery) or complex treatment (e.g., monitored bed) & is most likely to have a prolonged (>6 months) adverse effect on outcome *
5	Significant neural injury (i.e., 1 or more grade deterioration in ASIA grade) or serious life- or limb-threatening event or any sentinel event †
6	AE resulting in death

* Any AE with a functionally significant (i.e., patient reported) and most likely prolonged (>6 months) adverse effect on outcome, regardless of required treatment (e.g., nerve root injury that cannot be treated), should be Grade 4. ^† A sentinel event is an unexpected, serious life- or limb-threatening event(s) or any event (e.g., wrong level surgery) that necessitates a formal institutional review process and reporting as defined by your specific institution.