A clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms of asthma. One hundred participants are enrolled in the study and randomized to receive either the experimental medication or placebo. The primary outcome is self-reported reduction of symptoms. Among 50 participants who receive the experimental medication, 30 report a reduction of symptoms as compared to 15 participants of 50 assigned to the placebo. Generate a 95% CI for the difference in proportions of participants reporting a reduction of symptoms between the experimental and placebo groups.

Recently findings have been reported from a prospective cohort study that demonstrated a significant positive association between coffee consumption and increased risk of coronary heart disease. The authors reported a 21/2 fold increased risk among those drinking 5 or more cups of coffee daily, with a 95% CI from 1.08 to 5.77. Based on these data, PH office recommended people limit their coffee drinking to 2 cups or less per day. On what basis do you agree or disagree with this recommendation?

A clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms of asthma. One hundred participants are enrolled in the study and randomized to receive either the experimental medication or placebo. The primary outcome is self-reported reduction of symptoms. Among 50 participants who receive the experimental medication, 36 report a reduction of symptoms as compared to 17 participants of 50 assigned to the placebo. Generate a 95% CI for the difference in proportions of participants reporting a reduction of symptoms between the experimental and placebo groups.

Most cases of cervical cancer are linked to a few strains of the human papilloma virus (HPV). The pharmaceutical company Merck developed a vaccine (Gardisil) against these HPV strains. Worldwide clinical trials followed young women after vaccination or administration of placebo for two to four years for signs of HPV-caused cervical cancer. Based on a sample of 100 women in the Gardisil group, 24 % developed cervical cancer, and based on a sample of 100 women in the placebo group, 34 % developed cervical cancer. Test the claim that the proportion of women who developed cervical cancer in the Gardisil group is less than the proportion of women who developed cervical cancer in the placebo group at a = 0.10. Round your answers to three decimal places, and round any interim calculations to four decimal places. Fill in the hypotheses below where p₁ denotes the proportion of women who developed cervical cancer in the Gardisil group and P2 denotes the proportion of women who developed cervical…

Denny studied factors affecting cardiovascular reactivity to a postural change in a sample of healthy men and women. Change in systolic blood pressure (SBP) from supine to standing position was used as the measure of cardiac reactivity in a sample of 842 adults. Supine measurement of blood pressure was taken after participants had lain on an examination table for 15 minutes. Blood pressure was determined every 30 seconds using a Dinamap device for 2 minutes, and the measurements were averaged. Participants then stood up immediately, and additional measurements were made for another 2 minutes. Below is a table describing the characteristics of Denny’s sample: Which measures of dispersion, if any, are presented in this table (Ranges, SDs)? If age is normally distributed, approximately what percent of the sample would be younger than 50? If BMI is normally distributed, approximately what percent of the sample would have a BMI higher than 33.1?

A randomized controlled trial was conducted to determine whether treatment with daily aspirin was more effective than placebo at preventing myocardial infarction (MI) (within 5 years).   A total of 140 out of 11,140 subjects in the aspirin group experienced an MI, while 240 out of 11,040 subjects in the placebo group experienced an MI.  The relative risk of MI comparing aspirin to placebo was calculated to be 0.58, and its 95% confidence interval ranged from 0.47 to 0.71.  Which of the following can be concluded from these results?   Question 4 options:   On average, the risk of MI among subjects who used aspirin was 0.58 times the risk of MI among those on placebo.   On average, aspirin reduced the risk of MI in this population by 58% when compared to placebo.   Aspirin is almost certainly harmful to this population.   Compared to placebo, aspirin did not reduce the risk of MI by a statistically significant amount.