You are interested in multiple sclerosis (MS), an autoimmune disease that affects the central nervous system, and whether the drug, Avonex, is effective in reducing MS neurological and cognitive symptoms of MS. Participants were randomized into the Avonex group (n=197) or the Placebo group (n=193), with a 60-month (5 year) follow up period. Using "Multiple_Sclerosis_HMWK2" data file, the variables of interest are: . TREATMENT GROUP . 0=PLACEBO o 1 =AVONEX . GENDER 0 0=MALE o 1=FEMALE . RACE o 1=BLACK o 2=WHITE o 3=HISPANIC 0 4=OTHER . AGE (YEARS) . Adults ranging from 20 years and older. . BASELINE EDSS GROUP The EDSS is a composite score based upon an extensive neurological exam of 7 function systems and an ambulation component. Based upon baseline EDSS scores, subjects have been classified into three groups. A lower EDSS score indicates better patient functioning. . 1= 6.0 . BASELINE PASAT3 The PASAT 3 (Paced Auditory Serial Addition Test with a 2-second inter-stimulus interval) is measured as the number of correct responses (total possible 60). It can be treated as a continuous variable and is used to measure cognitive function. The higher the score, the better the cognitive function. . MONTH 60 PASAT3 . The PASAT 3 at 5 years (60 months) . PASAT3 Change . A computed variable (60 months PASAT 3 minus Baseline PASAT 3). A positive value indicates an increase in PASAT 3 scores while a negative value indicates a decrease in PASAT 3 scores