This index evaluates muscle symptoms using several domains that encompass the statin regimen (location and pattern of muscle symptoms, timing of muscle symptom onset in relation to starting statin regimen, timing of muscle symptom improvement after withdrawal of statin); timing of recurrence after rechallenge with the statin regimen; and previous symptoms on statin regimen prior to the current exposure. A score is selected on the basis of the patterns in the different domains. A total score is used to assess the likelihood of the patient's muscle symptoms from statin use. A score of ≤4 is "unlikely," 5 to 8 is "possible," and 9 to 11 is "probable."
