HW1: Measures of frequency
- Due Sep 13, 2021 at 3pm
- Points 100
- Questions 12
- Available after Aug 30, 2021 at 5pm
- Time Limit None
Instructions
Scenario A:
In a study by Doll et al (R. Doll and A. B. Hill, 'Smoking and carcinoma of the lung: preliminary report', BMJ, 1950;2:746), investigators compared the smoking history of a group of hospitalized patients with lung cancer with the smoking history of a similar group without lung cancer. Data for this study were collected from hospitalized patients in London and the surrounding communities over a four-year period (April 1948 to February 1952). Hospital personnel at more than 20 hospitals were asked to contact investigators whenever a patient was admitted with a new diagnosis of lung cancer. These patients were then interviewed about their previous smoking habits. Investigators interviewed a sample of patients from the same hospitals to identify controls at the outset of the study, but with different illnesses, about their smoking habits.
Scenario B:
A new nasal spray flu vaccine was tested in the fall of 2002 by immunizing 1,000 children who did not have rash or fever. Eleven of the 1,000 developed new rash and fever within 3 days. This study helped to raise the questions as to whether the nasal spray flu vaccine was related to side-effects.
Scenario C:
In 01/01/91, 6989 subjects 55 years of age or older who were free of dementia were enrolled. Each cohort member was followed until a diagnosis of dementia, death, loss to follow-up, or the end of the study period (2001). There was substantial loss to follow-up and death among participants over the ten years of follow-up, and the 6,989 subjects contributed 24,945 person-years of follow-up. Incidence of Alzheimer’s disease was estimated for those who used NSAIDs as documented in pharmacy records versus those who did not, and those measures were compared.