Question

Exercises 6.61 to 6.68 refer to a study published in the Journal of the American Medical Association and reported in the Sacramento Bee on January 26, 2000 (“Study Ties Hormone Replacement, Cancer” by Shari Roan, p. A1). A sample of 46,355 postmenopausal women were studied for 15 years and asked about their use of hormone therapy and whether or not they had breast cancer; 2082 developed the disease. The article reported that “for each year of combined [estrogen and progestin] therapy, a woman’s risk of breast cancer was found to increase by 8 percent compared to a 1 percent increase in women taking estrogen alone.”

6.62 Discuss whether this research is the following:

a. A case–control study.

b. A retrospective study or a prospective study

Answer 1

Correct option:

(a) Case Control Study

EXPLANATION:

Here, the requirement of two groups differing in outcome as per Case Control Stusy is met. The two groups are (i) women taking combined [estrogen and progestin] therapy and (ii) women taking estrogen alone.

Case Control Study is an Observational Study in which two existing groups differing in outcome are identified and compared on the basis of some causal attribue.

Retrospective Study looks backwards and examines exposures to suspected risk or protection factors in relation to an outcome that is established at the start of the study.

Prospective Study watches for outcomes, such as the development of a disease, during the study period and relates this to other factors such as suspected risk of protecion factors.