A study was designed to assess the effect of echinacea extracts on the rates of

Question

A study was designed to assess the effect of echinacea extracts on the rates of infection of individuals voluntarily exposed to the common-cold rhinovirus. Some subjects took an echinacea extract daily starting 7 days before viral exposure until the end of the study. Another group of subjects received the extract from the time of viral exposure onward only. A last group received just an inactive solution ("placebo group"). The table below is a two-way table of the diagnosed clinical colds among infected subjects in each treatment group. The following exercises are based on the table below.

Weak associationNo association    Strong association

Cold No cold Total 7 days before viral exposure and onward 77 61 138 From time of viral exposure onward 89 44 133 Placebo (no echinacea) 51 30 81 <td '="">Total 217 135 352 70% ONo cold OC old 10% 7 days betbre From time of Placebo (no iral exposure iral exposure echinacea) and onward on vard

Explanation / Answer

a)

percent of the subjects in the "7 days before viral exposure and onward" group were diagnosed with a cold=(77/138)*100 =55.80% ~ 56.0%

b) percent of the subjects in the "From time of viral exposure onward" group were diagnosed with a cold =(89/133)*100=66.92% ~ 67.0%

c)

percent of the subjects in the "Placebo (no echinacea)" group were diagnosed with a cold

=(51/81)*100=62.96% ~ 63.0%

d)

No association

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.