MERS-TM provides a guide for establishing the level of patient risk for each event. That guide is the Risk Assessment Index or RAI.

RISK = SEVERITY X PROBABLILITY OF RECURRENCE

Therefore, values for both severity and probability of recurrence must be estimated.

On the Risk Assessment Index:

• Severity is the Quantified Estimate of Severity of patient harm or QES.
  
  
• Probability is the Quantified Estimate of Probability of recurrence or QEP