The Statin-Associated Muscle Symptom Clinical Index (SAMS-CI): Revision for Clinical Use, Content Validation, and Inter-rater Reliability

Cardiovasc Drugs Ther. 2017 Apr;31(2):179-186. doi: 10.1007/s10557-017-6723-4.


Purpose: The Statin-Associated Muscle Symptom Clinical Index (SAMS-CI) is a method for assessing the likelihood that a patient's muscle symptoms (e.g., myalgia or myopathy) were caused or worsened by statin use. The objectives of this study were to prepare the SAMS-CI for clinical use, estimate its inter-rater reliability, and collect feedback from physicians on its practical application.

Methods: For content validity, we conducted structured in-depth interviews with its original authors as well as with a panel of independent physicians. Estimation of inter-rater reliability involved an analysis of 30 written clinical cases which were scored by a sample of physicians. A separate group of physicians provided feedback on the clinical use of the SAMS-CI and its potential utility in practice.

Results: Qualitative interviews with providers supported the content validity of the SAMS-CI. Feedback on the clinical use of the SAMS-CI included several perceived benefits (such as brevity, clear wording, and simple scoring process) and some possible concerns (workflow issues and applicability in primary care). The inter-rater reliability of the SAMS-CI was estimated to be 0.77 (confidence interval 0.66-0.85), indicating high concordance between raters. With additional provider feedback, a revised SAMS-CI instrument was created suitable for further testing, both in the clinical setting and in prospective validation studies.

Conclusions: With standardized questions, vetted language, easily interpreted scores, and demonstrated reliability, the SAMS aims to estimate the likelihood that a patient's muscle symptoms were attributable to statins. The SAMS-CI may support better detection of statin-associated muscle symptoms in clinical practice, optimize treatment for patients experiencing muscle symptoms, and provide a useful tool for further clinical research.

Keywords: Clinical measurement; Inter-rater reliability; Muscle symptoms; Myalgia; Myopathy; Statin adverse events; Statin intolerance; Statin-associated muscle symptoms.

Publication types

  • Validation Study

MeSH terms

  • Feedback, Psychological
  • Humans
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / adverse effects*
  • Interviews as Topic
  • Language
  • Muscle, Skeletal / drug effects*
  • Muscle, Skeletal / pathology
  • Muscle, Skeletal / physiopathology
  • Myalgia / chemically induced*
  • Myalgia / diagnosis
  • Myalgia / physiopathology
  • Observer Variation
  • Predictive Value of Tests
  • Qualitative Research
  • Reproducibility of Results
  • Risk Assessment
  • Risk Factors
  • Surveys and Questionnaires*
  • Workflow


  • Hydroxymethylglutaryl-CoA Reductase Inhibitors