Studies are often done by pharmaceutical companies to determine the effectiveness of a treatment program. Suppose that a new AIDS antibody drug is currently under study. It is given to patients once the AIDS symptoms have revealed themselves. Of interest is the average (mean) length of time in months patients live once starting the treatment. Two researchers each follow a different set of 40 AIDS patients from the start of treatment until their deaths. The following data (in months) are collected.Researcher A: 3; 4; 11; 15; 16; 17; 22; 44; 37; 16; 14; 24; 25; 15; 26; 27; 33; 29; 35; 44; 13; 21; 22; 10; 12; 8; 40; 32; 26; 27; 31; 34; 29; 17; 8; 24; 18; 47; 33; 34Researcher B: 3; 14; 11; 5; 16; 17; 28; 41; 31; 18; 14; 14; 26; 25; 21; 22; 31; 2; 35; 44; 23; 21; 21; 16; 12; 18; 41; 22; 16; 25; 33; 34; 29; 13; 18; 24; 23; 42; 33; 29Suppose that the first researcher conducted his survey by randomly choosing one state in the nation and then randomly picking 40 patients from that state. What sampling method would that researcher have used?

Think back to the example study earlier in this lecture. The researchers followed 3 participants in a 5 year study. You have already calculated the total person-time and found out that it is 10 years. During the study, there was one case of the disease. Calculate the rate. 101.13.33

Identify which statement is most accurate about current HIV research and treatment.Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer.aWith treatment, people with HIV can now expect to live an average life expectancy.bPREP when taken consistently can prevent transmission of HIV by up to 90%. cThere is a currently an HIV vaccine in phase 3 trials that is expected to release to the public by 2026. dBoth A & B are correct.

The researchers followed 3 participants in a 5 year study. Begin by calculating the person-time for each participant. Then, calculate the total person-time by adding up the three individual person-times. If you find it helpful, you might want to create a graph to help visualize this information. What is the total person-time in this study?Participant 1: Year 1: follow-up, Year 2: lost to follow-up at the end of the yearParticipant 2: Year 1: follow-up, Year 2: follow-up, Year 3: follow-up, Year 4: disease at the end of the yearParticipant 3: Year 1: no observation, Year 2: follow-up, Year 3: follow-up, Year 4: follow-up, Year 5: death at the end of the year10 years 8 years 7 years 15 years

In an epidemic curve for a common point source epidemic we can confidently estimate the possible timing of exposure of most cases using:Select one alternative:A) The date of report of the index case minus the mean incubation periodB) The date of report of the last group of cases minus the maximum incubation periodC) The date of report of the first case after the index case minus the minimum incubation periodD) Both B + C

You design a study to evaluate the effect of a new treatment for an anxiety disorder.  In the study, one group of participants (Group 1) receive the new treatment for 1 hour per week, for 8 weeks. Another group of participants (Group 2) receive nothing for 8 weeks, they are waiting to receive the treatment later.  Before the treatment and after the treatment, you measure the level of anxiety in both groups.  At the end of the treatment, you find that both groups improved slightly, and to the same degree.  What is your conclusion?