02-03-2006, 06:53 AM
1) in a cohort study 2 groups are studies ...10000 pple who consume alcohol and 10000 who do not....they are followed for developement of bladder cancer .result sshow that those who consum ealcohol have increased risk for bladder cancer that is statistically significant at 5 % level .wht is teh correct interpretation?
a) at least 5 % of bladder ca can be attributed to alc consumption
b)at least 5 % of alc consumers dev bladder ca
c) such an effect would occur by chance is less than 5 % of reapeated samples
d) there is at least 5 % increased risk for bladder ca among alv consumers
e) men who drink alc are 5 times more likely to dev bladder ca than those who do not drink alc
2)the foll table showa survival info of those who had an operation for a particular type of cancer:
interval pts at strt pts who died surviving pts
0-1 yr 500 100 80%
1-2 yr 400 50 87.5%
2-3 yr 350 35 90%
3-4 yr 315 31 90%
based on this info if a pt survives for 1 yr what is teh probablity that he will survive for 4 yrs?
a) (0.875 -0.8)o.9 =o.o675
b) 0.8*o.875*o.9*0.9=0.567
c) 0.875*0.9=0.7875
d) 0.875*0.9*0.9=0.7088
e)o.9
f)0.9-0.875=0.025
a) at least 5 % of bladder ca can be attributed to alc consumption
b)at least 5 % of alc consumers dev bladder ca
c) such an effect would occur by chance is less than 5 % of reapeated samples
d) there is at least 5 % increased risk for bladder ca among alv consumers
e) men who drink alc are 5 times more likely to dev bladder ca than those who do not drink alc
2)the foll table showa survival info of those who had an operation for a particular type of cancer:
interval pts at strt pts who died surviving pts
0-1 yr 500 100 80%
1-2 yr 400 50 87.5%
2-3 yr 350 35 90%
3-4 yr 315 31 90%
based on this info if a pt survives for 1 yr what is teh probablity that he will survive for 4 yrs?
a) (0.875 -0.8)o.9 =o.o675
b) 0.8*o.875*o.9*0.9=0.567
c) 0.875*0.9=0.7875
d) 0.875*0.9*0.9=0.7088
e)o.9
f)0.9-0.875=0.025