A randomized trial studied 242 HIVseropositive 2ndtrimester

A randomized trial studied 242 HIV-seropositive, 2nd-trimester pregnant women to assess the efficacy of zidovudine (AZT) in preventing perinatal HIV transmission.  Results were:

Zidovudine        

Placebo           

All

Births (#)

121

121

242

Infection status of infant

  Non-infected (#)

112

90

202

  Infected (#)

9

31

40

Transmission rate (%)

7.4

25.6

16.5

Which one answer best describes the data in the

Solution

a)Count best describes the non-infected row in the table as it is calculated out of total of 242

b)Here in the trans missionr rate the best it describes is the proportion as

c) relative risk of HIV infection for infants whose mothers took zidovudine relative to infants of mothers who took placebo =(transmission rate of zidovudine)/(transmission rate of placebo)=7.4/25.6 =.289