Anti-fungal treatment (Fitzmaurice exercise 14.1) A randomized double -blind , parallel group study was performed to compare two anti - fungal treatments 0 = 200mg /day Itraconazole 1 = 250 mg/day Terbinafine for toenail infenction. A total of 294 patients were evaluated for severity of the symptom onycholysis (0=none or mild and 1=moderate or severe) at baseline and with planned follow up visits after 4, 8, 12, 24, 36, and 48 weeks . The main objective of the study was to compare the effects of the two treatments on the change in risk of onycholysis over the duration of the study. 1. Read data into SAS from the file onycholysis . txt and transform it from the wide to the long format . Compute the prevalence of onycholysis in the two groups for each separate visit . 2. The time - variables s in the data contain the time (in months after baseline when the visit took place . Convert this to weeks and compute summary stati stics to investigate whether visits took place according to what was planned. 3. Fit a suitable population average model describing the prevalence of ony- cholysis in the two treatment groups at the various visit and using an un- structured working covariance. . Compute the odds ratios for change in prevalence from first to last visit in each of the two groups . Do the odds ratios differ significantly between the treatments . Make a plot displaying the estimated prevalences of onycholysis over time in the two groups . Do we see a logit - linear decrease with time ? 4. In Fitzmaurice et al (201 1 ) it was suggested to model time as a continuous effect (use the time - variable). Hence, fit the following model for the mean: logit {E (Y, ) = B, + B2 time + B, treatment x time (1) This seems reasonable only when looking at visits I through 5, so from now on we will exclude data from visits 6 and 7. . What is the estimated decrease in odds of onychololysis per month with each of the two treatments, respectively