Excellent inter-rater, intra-rater, and telephone-administered reliability of the ALSFRS-R in a multicenter clinical trial

Amyotroph Lateral Scler. 2007 Feb;8(1):42-6. doi: 10.1080/17482960600888156.


We wished to determine whether the Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRS-R) is reliable when used as primary outcome measure in a multicenter clinical trial. To establish inter-rater reliability, we randomly assigned 19 primary raters and 11 back-up raters to score nine amyotrophic lateral sclerosis (ALS) patients using the ALSFRS-R. To assess intra-rater reliability and reliability of telephone administration, we randomly assigned consecutive participants of the Clinical Trial of High Dose Coenzyme Q10 in ALS (QALS) to have in-person ALSFRS-R interviews at both screening and baseline visits (n=41 patients) or to have the ALSFRS-R interview by telephone at screening and in person at the baseline visit (n=27). An intraclass correlation coefficient (ICC) of reliability was calculated using a one-way random effects analysis of variance model. In the inter-rater reliability assessment, the primary raters performed 54 ratings on nine patients with ICC=0.93 (95% CI 0.84-0.98). For back-up raters, 32 ratings on nine patients resulted in ICC=0.93 (95% CI 0.82-0.98). The intra-rater reliability for in-person interviews was ICC = 0.95 (95% CI 0.92-0.98). The reliability of telephone administration compared to in-person interviews was ICC=0.97 (95% CI 0.93-0.98). We conclude that the ALSFRS-R shows excellent inter- and intra-rater reliability, and reliability of telephone administration when used as primary outcome measure in a multicenter ALS trial.

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Activities of Daily Living
  • Amyotrophic Lateral Sclerosis / drug therapy
  • Amyotrophic Lateral Sclerosis / physiopathology*
  • Caregivers / psychology*
  • Coenzymes
  • Double-Blind Method
  • Humans
  • Reproducibility of Results
  • Retrospective Studies
  • Severity of Illness Index*
  • Sickness Impact Profile*
  • Telephone / instrumentation
  • Ubiquinone / analogs & derivatives
  • Ubiquinone / therapeutic use
  • Vitamins / therapeutic use


  • Coenzymes
  • Vitamins
  • Ubiquinone
  • coenzyme Q10