Internal consistency and test-retest reliability of the MGFS have been examined with both MG patients and volunteers without MG.
Those who consented to participate were asked to fill out the four questionnaires: the Demographic and Clinical Data form, CFS, MGFS, and CES-D scale.
Three days after the clinic visit, a new copy of the MGFS, along with a self-addressed, stamped envelope, was mailed to each participant to allow retest within 5 to 7 days of initial testing.
Pearson's product-moment correlation coefficient was calculated to determine test-retest reliability of the MGFS, and Cronbach's alpha calculation was employed to examine internal consistency of the MGFS and other appropriate instruments used in the study.
The initial administration of the MGFS for 67 participants was used to examine the internal consistency of the instrument.
For the 1-week retest of the MGFS, 49 of the 67 participants mailed the questionnaire back within 7 days of the initial test, 16 did not return the questionnaire, and 2 returned the questionnaire too late for it to be analyzed.
A summary of the stepwise multiple regression analysis for the MGFS with 65 participants is presented in Table 4.
The MGFS demonstrated adequate internal consistency.
056), because the MGFS score indicates physical fatigue and the MQMG score indicates muscle weakness.
Low positive correlations were found between the MGFS score and the CFS scores for physical, mental, and total fatigue.
Low correlation between the MGFS and CFS may also be due to differences in emphasis.
The current findings showed a moderate correlation between depression score and the MGFS score (r = .