The data for patients give below who went through blood pressure monitoring has been uploaded to the SAS server (also uploaded in the class schedule). Each column in the file is tab separated from the other. (Note: Data in the file is same as the data you analyzed for your second assignment. So, you should already know how to read the data from the file to create the SAS dataset. But please bear in mind that you would be performing different analysis on this data in this assignment)
First column contains patient's Gender (1=male 2= female) Second column contains patient's Age Third column contains patient's Systolic blood pressure Fourth column contains patient's Diastolic blood pressure
As an investigator of a clinical trial, you are interested to examine if gender (male and female) has a role to play on blood pressure of the 161 randomly selected subjects in your dataset.
Question 1: One of your co-investigators is claiming that in general, Systolic blood pressure of women is always lower than that of men.
Question 1A: Based on the lecture on t-test and the dataset you have (explained above), which type of t-test is most appropriate to investigate your co-investigator's claim? Why is it most appropriate t- test? Please explain your answer in 1-2 lines.
Question 1B: In SAS, run the appropriate t-test you chose in Question 1A to verify your co- investigator's claim. Is his claim valid? According to your SAS output, explain why his claim is or isn't valid. Provide SAS code, SAS output and explanation of your answer in 1-2 lines.
Question 2: As part of your investigation, you gave all the subjects a drug to reduce Systolic blood pressure and observed their Systolic blood pressure before and after taking the drug.
Question 2A: Consider the same data file as explained above and replace the variable Systolic blood pressure (third column of the data file) with Systolic blood pressure before taking the drug and also replace the Diastolic blood pressure (last column of the data file) with Systolic blood pressure after taking the drug. Notice you have two variables now, ‘Systolic before' and ‘Systolic after' instead of Systolic and Diastolic blood pressure respectively on the same subjects (161 males and females). (Please note that you are just renaming the columns, the data remains the same.)
Question 2B: You are claiming that the drug decreases the Systolic blood pressure in the subjects. Perform a paired t-test to verify your claim. Is your claim valid? Provide the appropriate t- test SAS code, SAS output and explain in 1-2 lines if your claim is or isn't valid based on your observation.
Data Set: 1 55 124 88 2 52 128 86 1 63 126 64 1 83 154 54 2 37 104 70 2 50 118 78 2 55 130 86 1 40 126 88 2 37 100 56 2 57 164 70 1 21 122 66 2 85 138 66 2 84 124 54 1 69 124 68 1 55 132 82 2 37 106 76 2 59 110 76 2 73 218 94 1 78 148 84 2 51 128 68 1 71 130 62 1 69 170 92 1 52 116 78 1 25 132 76 2 57 108 72 1 70 130 58 1 85 182 66 2 60 170 86 2 80 202 76 2 57 122 74 1 26 104 58 1 28 114 70 1 56 144 90 2 25 102 56 2 64 132 56 2 68 106 58 1 75 144 70 1 70 116 64 1 26 114 64 1 20 126 74 1 25 124 78 1 76 148 68 1 81 122 54 2 32 104 66 2 38 128 78 2 63 132 72 1 66 140 66 2 60 108 58 2 37 100 74 1 75 158 88 1 55 152 76 1 36 112 68 1 37 114 80 2 20 108 70 1 59 120 74 1 85 136 54 1 72 106 62 2 31 120 72 2 31 126 86 2 63 168 86 1 27 124 82 2 67 172 86 2 71 156 78 2 51 112 74 2 60 146 82 1 65 140 60 2 20 88 50 1 51 114 72 2 69 176 84 2 43 142 100 2 45 118 60 2 61 128 64 1 73 144 50 2 47 162 86 1 61 166 70 2 80 180 80 1 40 138 96 2 29 100 66 1 26 118 52 1 85 138 32 1 62 158 88 2 40 166 88 1 20 102 62 2 54 130 76 2 23 124 82 2 51 116 68 1 23 130 88 1 74 148 52 1 21 112 68 2 44 102 60 1 23 114 82 2 34 120 68 2 26 108 40 1 24 128 82 2 49 128 76 1 38 122 76 1 26 124 72 1 31 108 70 2 62 110 72 1 85 160 58 2 67 116 60 1 26 126 82 1 41 122 76 1 43 136 64 2 85 128 44 1 45 120 90 1 44 138 94 2 26 110 74 2 65 142 58 2 22 106 54 1 41 108 70 1 37 132 86 1 63 108 68 2 83 178 82 2 34 100 62 2 64 144 66 1 75 108 68 2 64 122 64 2 72 134 64 1 50 128 84 2 22 108 66 2 22 120 54 2 61 100 58 1 41 136 84 2 32 122 60 2 28 100 74 1 32 134 84 1 51 126 82 2 61 118 62 1 41 100 68 2 43 108 74 1 50 122 66 2 63 152 80 1 42 114 74 2 40 92 70 1 44 110 62 2 43 126 66 2 36 122 78 1 45 140 80 2 44 124 78 1 68 136 54 1 54 144 64 1 21 110 58 2 51 102 62 1 61 142 64 1 77 126 60 1 66 116 70 2 77 116 54 2 61 152 74 2 42 110 80 2 78 140 26 2 45 98 76 1 59 124 74 1 23 122 64 2 58 160 74 1 39 138 90 2 37 120 68 1 35 114 68 1 41 118 78 2 24 108 58 1 30 124 82