Grade 1 - all of the following:
(1) no outpatient medical care
(2) <= 2 weeks in duration (typically shorter)
(3) resolved with no or minimal intervention
Grade 2 - one or more of the following:
(1) outpatient medical care
(2) duration > 2 weeks and <= 6 months
(3) any limitation in activities of daily living <= 2 weeks
Grade 3 - both of the following:
(1) not life-threatening
(2) one or more of the following:
(2a) requires hospitalization
(2b) duration > 6 months
(2c) limitation in activities of daily living > 2 weeks
(2d) requires surgery
(2e) other serious complication
Grade 4: requires immediate medical intervention to prevent death
Grade 5: fatal
