ACCURACY, REPRODUCIBILITY AND VARIABILITY OF QUANTITATIVE ASSESSMENTSOF BULBAR AND RESPIRATORY-FUNCTION IN MOTOR-NEURON DISEASE

The validity of quantitative tests to assess bulbar and respiratory fu nction used in therapeutic trials in motor neurone disease (MND) is st udied in 26 MND and 21 age- and sex-matched control subjects. Five rat ers timed repeated visual and auditory stimuli generated by a metronom e simulating bulbar tests. For all raters, mean error rate was 5.07%, correlation coefficient was 0.89 (and % difference of 1.53), and coeff icient of variation (CV) was 3.18%. The experienced rater obtained sig nificantly better % differences and CV. For all subjects and tests, me an correlation coefficient was 0.98, and mean CV was 8.8%. There were no significant differences in reproducibility or variability in readin gs obtained in MND and control subjects assessed by the experienced ra ter. The use of composite bulbar, but not respiratory, scores resulted in significant improvements in reproducibility and variability.