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a pharmaceutical company researcher is working on drugs x,y and z proposed for the treatment of diabetes mellitus.He selects a group of 300 diabetic people in Jackson,TN.He randomly divides them into 3 groups of 100 each(a,b and c)for the purpose of this study.Group a recieves drug x,group b receives drug y and group c receives drug z.He follows them prospectively for 6 months and tabulate the results:

Drug= x:group =a:SD=2, mean serum glucose levels(mg/dl)=85, 95% C I:84.6-85.4

Drug= y:group =b:SD=2.33, mean serum glucose levels(mg/dl)=87, 95% C I:86.5-87.47

Drug= z:group =c:SD=3.32, mean serum glucose levels(mg/dl)=83, 95% C I:82.44-83.56

whichof the following satements is correct:

a.this study is invalid because sample selection is improper
b.drug x is most potent among all three drugs
c.there is no statistically significant difference between the effect of drug x and z
d.drug x has the widest range of effect
e.drug y will result in significant increase in mortality in diabetic patients if used on regular basis

sorry there is some typo error in first one ,this is the q this is the q with correction:


a pharmaceutical company researcher is working on drugs x,y and z proposed for the treatment of diabetes mellitus.He selects a group of 300 diabetic people in Jackson,TN.He randomly divides them into 3 groups of 100 each(a,b and c)for the purpose of this study.Group a recieves drug x,group b receives drug y and group c receives drug z.He follows them prospectively for 6 months and tabulate the results:

Drug= x:group =a:SD=2, mean serum glucose levels(mg/dl)=85, 95% C I:84.6-85.4

Drug= y:group =b:SD=2.33, mean serum glucose levels(mg/dl)=87, 95% C I:86.5-87.47

Drug= z:group =c:SD=3.32, mean serum glucose levels(mg/dl)=83, 95% C I:82.44-83.56

whichof the following satements is correct:

a.this study is invalid because sample selection is improper
b.drug x is most potent among all three drugs
c.there is no statistically significant difference between the effect of drug x and z
d.drug z has the widest range of effect(effective in some pts and not effectove in some)
e.drug y will result in significant increase in mortality in diabetic patients if used on regular basis

d ......hi junaid apologies for not being too active....net down using phone net

DDD

D is correct.
what about B? why isn't correct?

i have the same doubt as karim12345.. can anyone explain plz? thanx..

correct ans is d
CI is calculated by the following formula
CI=mean+-standard score z x standard error of mean
standard error of mean is calculated by dividing the SD by square root of sample size(N).As the the SD increases,the standard error increases and so does the confidence interval.As N icreases standard error decreases.
since drug z has the widest range of CI it has widest range of effects.

Choice B is wrong because this study doesnt tell anything about potency.