The EDSS is used to quantify disability due to symptoms of MS and to track changes in disability status over time. Scores range from 0 (normal neurological exam) to 10 (death due to multiple sclerosis).

The WPAI questionnaire is a validated instrument to measure impairments in work and activities. The WPAI yields four types of scores: 1. Absenteeism (work time missed) 2. Presenteesism (impairment at work / reduced on-the-job effectiveness) 3. Work productivity loss (overall work impairment / absenteeism plus presenteeism) 4. Activity Impairment. WPAI outcomes are expressed as impairment percentages ranging from 0-100%, with higher numbers indicating greater impairment and less productivity.

The FSS is a self-assessment questionnaire that provides a score as a measurement of the severity of fatigue. It consists of 9 questions scored from 1 to 7. A low value (e.g., 1); indicates strong disagreement with the statement, whereas a high value (e.g., 7); indicates strong agreement. A total score of 36 or more suggests presence of fatigue.

MSFC has 2 component- timed 25-foot walk (T25FW) and 9-hole peg test (9HPT) [dominant and nondominant hands]. The MSFC Z-score is calculated by creating Z-scores for each component of the MSFC and averaging them to create an overall composite score. MSFC Z-score = (Z25-foot-walk + Z9HPT-2)/2, where Zj refers to Z-scores of component j. A Z-score represented the number of standard deviations participant's test result was higher (Z >0) or lower (Z <0) than the average test result (Z = 0) from the reference population. Higher scores indicate better outcomes.

BDI-II Scale is a 21-item self-reported questionnaire which measures the existence and severity of symptoms of depression. Each of the 21 items on BDI-II tool represents a depressive symptom. The symptoms are each scored on a 4-point Likert scale of 0 to 3 (0=symptom is absent; 3=symptom is severe). Scores for each symptom are added up to obtain the total scores for all 21 items. Total score ranges from 0-63; of which 0-8 is considered no depression, 0-13 is minimal depression, 14-19 is mild depression, 20-28 is moderate depression and 29-63 is severe depression.

MSIS-29 is a brief self-administered instrument measuring physical (20 items) and psychological (9 items) impact of Multiple Sclerosis (MS). Each of the 29 items on MSIS-29 tool is a question that ask for participants views about the impact of MS on their day to day lives. Each item is scored on 1 to 5 (1=Not at all; 5=Extremely).