Question

Paragraph Styles Refer to the following for text for the questions below A causal r 1920s on the basis of clinical observations. To test this apparent association, numerous epidemiologic studies were undertaken between 1930 and 1960. Two studies were conducted by Richard Doll and Austin Bradford Hill in Great Britain. The first was a case-control study begun in 1947 comparing the smoking habits of lung cancer patients with the smoking habits of other patients. The second was a cohort study begun in 1951 recording causes of death among British physicians in relation to smoking habits. This case study deals with the case- control study cigarette smoking and lung cancer was first suspected in the Data for the case-control study were obtained from hospitalized patients in London and vicinity over a 4-year period (April 1948- February 1952) Initially, 20 hospitals, and later more, were asked to notify the investigators of all patients admitted with a new diagnosis of lung cancer. These patients were then interviewed concerning smoking habits, as were controls selected from patients with other disorders (primarily non-malignant) who were hospitalized in the same hospitals at the same time. 1. What other sources of cases and controls might have been used? 2. How representative of all persons with lung cancer are hospitalized patients with 3. How representative of the general population without lung cancer are lung cancer? hospitalized patients without lung cancer? How may these representativeness issues affect interpretation of the study's esults?

Answer 1

1)The other sources of cases and controls could be found at doctors office, insurance claims and files, death certificates and any cancer registries. 2)Patients hospitalized are fairly representative because it is likely a patient with lung cancer has been admitted to the hospital, and they are various stage of lung cancer and those hospitalized could have different stages or be sicker. 3)it is uncommon to be in the hospital therefore persons in the hospital are considered not normal interms of the general population , not very representative. 4) controls in the hospital could be there for other disease such as chronic obstructive pulmonary disease, the rates of smoking are higher in hospitals than the general populations, the higher rates of smoking in the control group can underestimate the lung cancer rates from smoking.