29.

In an August 2013 article published in American Journal of Public Health, researchers report the results of a two-site (San Francisco and NYC) randomized trial: here is a description of the trial and itsstudy sample from the article abstract:

Objectives. We evaluated the efficacy of a hepatitis care coordination intervention to improve linkage to hepatitis A virus (HAV) and hepatitis B virus (HBV) vaccination and clinical evaluation of hepatitis C virus (HCV) infection among methadone maintenance patients. Methods. We conducted a randomized controlled trial of 489 participants from methadone maintenance treatment programs in San Francisco, California, and New York City from February 2008 through June 2011. We randomized participants to a control arm (n = 245) and an intervention arm (n = 244), which included on-site screening, motivational-enhanced education and counseling, on-site vaccination, and case management services. Of the 150 participants in the intervention group who needed the combined HAV--- HBV vaccine, 115 received the vaccine within 30 days of the vaccine being recommended. Of the 150 participants in the control group who needed the combined HAV-HBV vaccine,18 received the vaccine within 30 days of the vaccine being recommended.

- Estimate the relative odds (odds ratio) of getting the vaccine within 30 day of recommendation for the intervention group compared to the control group.

10.

A pilot study was designed to evaluate the potential efficacy of a program designed to reduce prison recidivism amongst inmates who have a documented long-term history of drug and/or alcohol problems. A sample of 11 prisoners was followed for up to 24 months after their most recent release from prison. Six of the inmates returned to prison at 3, 7 9, 11, 14 and 21 months respectively. Five of the inmates had not returned to prison as of the last time they were last contacted which was at 4, 8, 16, 24, and 24 months respectively.

Use the Kaplan Meier approach to estimate the survival curve for this set of inmates (which tracks the proportion who have not yet returned to prison over time). It will be helpful to construct a table like the ones appearing in lecture 5: however, all you will need to report in the quiz generator are certain quantities from this table for specific times.

-- What is the estimated proportion of the entire cohort (the starting sample of 11 prisoners) sample who had not returned to prison by 7 months after enrolling in the study?

12. A pilot study was designed to evaluate the potential efficacy of a program designed to reduce prison recidivism amongst inmates who have a documented long-term history of drug and/or alcohol problems. A sample of 11 prisoners was followed for up to 24 months after their most recent release from prison. Six of the inmates returned to prison at 3, 7 9, 11, 14 and 21 months respectively. Five of the inmates had not returned to prison as of the last time they were last contacted which was at 4, 8, 16, 24, and 24 months respectively.

Use the Kaplan Meier approach to estimate the survival curve for this set of inmates (which tracks the proportion who have not yet returned to prison over time). It will be helpful to construct a table like the ones appearing in lecture 5: however, all you will need to report in the quiz generator are certain quantities from this table for specific times.

- What is the estimated proportion of persons who did not return to prison at 11 months among only those who were still at risk of returning to prison at 11 months?

13. A pilot study was designed to evaluate the potential efficacy of a program designed to reduce prison recidivism amongst inmates who have a documented long-term history of drug and/or alcohol problems. A sample of 11 prisoners was followed for up to 24 months after their most recent release from prison. Six of the inmates returned to prison at 3, 7 9, 11, 14 and 21 months respectively. Five of the inmates had not returned to prison as of the last time they were last contacted which was at 4, 8, 16, 24, and 24 months respectively.

Use the Kaplan Meier approach to estimate the survival curve for this set of inmates (which tracks the proportion who have not yet returned to prison over time). It will be helpful to construct a table like the ones appearing in lecture 5: however, all you will need to report in the quiz generator are certain quantities from this table for specific times.

-What is the estimated proportion of the entire cohort ( the starting sample of 11 prisoners) sample who had not returned to prison by 16 months after enrolling in the study?