Biostatistics

EXERCISES 697
deficit in Sprague–Dawley rats. In the study, 10 rats were to receive MRZ 2/579 and nine rats were to
receive regular saline. Prior to treatment, researchers studied the blood gas levels in the two groups of
rats. The following table shows the pO 2 levels for the two groups.
Saline (mmHg)
MRZ 2/579 (mmHg)
112.5 133.3
106.3 106.4
99.5 113.1
98.3 117.2
103.4 126.4
109.4 98.1
108.9 113.4
107.4 116.8
116.5
Source: Data provided courtesy of Ludmila Belayev, M.D.
May we conclude, on the basis of these data, that, in general, subjects on saline have, on average,
lower pO 2 levels at baseline? Let a ¼ :01.
13.6.3 The purpose of a study by researchers at the Cleveland (Ohio) Clinic (A-6) was to determine if the use
of Flomax ® reduced the urinary side effects commonly experienced by patients following brachytherapy
(permanent radioactive seed implant) treatment for prostate cancer. The following table
shows the American Urological Association (AUA) symptom index scores for two groups of subjects
after 8 weeks of treatment. The higher the AUA index, the more severe the urinary obstruction and
irritation.
AUA Index (Flomax ® )
AUA Index (Placebo)
1 5 11 1 6 12
1 5 11 1 6 12
2 6 11 2 6 13
2 6 11 2 6 14
2 7 12 2 6 17
2 7 12 3 7 18
3 7 13 3 8 19
3 7 14 3 8 20
3 8 16 3 9 23
4 8 16 4 9 23
4 8 18 4 10
4 8 21 4 10
4 9 31 5 11
4 9 5 11
4 10 5 12
Source: Data provided courtesy of Chandana Reddy, M.S.
May we conclude, on the basis of these data, that the median AUA index in the Flomax ® group differs
significantly from the median AUA index of the placebo group? Let a ¼ :05.