MG-ADL and QMG disease measures were analyzed by treatment group and follow-up time for the 118 patients with at least one follow-up visit using generalized linear models with repeated measures (GLMs) and autocorrelation [AR(1)] covariance.  Models were compared to determine if both measures similarly captured the group difference and time trend in disease status. Model distributional assumptions were also evaluated.

Correlations between the measures were examined for the 123 patients having any observations. Multivariate relationships between QMG and MG-ADL means, standard deviations, and observed correlations were examined graphically and using multivariate ANOVA.

Assuming normality for QMG appears adequate, but MG-ADL is better fit by a Poisson distribution. Treatment group and time were significant (p<0.05) in both models. The AR(1) parameter was similarly high for QMG (0.8448) and MG-ADL (0.7225).  Visually the QMG model fits better overall and especially for TPP patients.

The baseline correlation between the measures was 0.65 (TPP) and 0.53 (PA).  The increasing multivariate relationship describing the observed correlation between the two measures and their means (HLT p<0.0001) and standard deviations (HLT p<0.0001) at each time point suggests the measures perform more similarly when the disease is less well controlled.