Question

Sample Problem #3:

The following information applies to questions a-d. An article was recently published on the relationship between caffeine consumption during pregnancy and low birth weight. The article was based on the results of a case-control study. As you know, caffeine is present in a wide variety of beverages, foods, and medications, including coffee, tea, and colas. The following statements have been taken from the introduction and results sections of the article. Select the Hill’s guideline that best describes each statement.

A. Caffeine exposure during pregnancy could have a harmful effect because caffeine interferes with cell division, metabolism, and growth. (2)

a. Consistency

b. Dose-response

c. Temporality

d. Biological plausibility

e. Strength of the association

B. Four prior case-control studies and three cohort studies of caffeine intake during pregnancy have shown an increased risk of low birth weight infants among women who consumed high amounts of caffeine. (2)

a. Consistency

b. Dose-response

c. Temporality

d. Biological plausibility

e. Strength of the association

C. In the current study, there was a four-fold increased risk (OR=4.0) of giving birth to a low birth weight infant among women who drank caffeine during pregnancy compared to women who did not consume any caffeine during pregnancy. (2)

a. Consistency

b. Dose-response

c. Temporality

d. Biological plausibility

e. Strength of the association

D. The risk of low birth weight increased as the caffeine consumption increased. Compared to women who did not consume any caffeine during pregnancy, the relative risk of giving birth to a low birth weight infant was 1.4 for women who had low caffeine consumption, 2.3 for women who had moderate caffeine consumption, and 5.6 for women who had high caffeine consumption. (2)

a. Consistency

b. Dose-response

c. Temporality

d. Biological plausibility

e. Strength of the association

Answer 1

Biological plausibility: Greater exposure should generally lead to greater incidence of the effect.

Consistency: Consistent findings observed by different persons in different places with different samples strengthens the likelihood of an effect.

Strength of the association: A small association does not mean that there is not a causal effect, though the larger the association, the more likely that it is causal.

Temporality: The effect has to occur after the cause.

A)

d. Biological plausibility

Option-(d)

B)

a. Consistency

Option-(a)

C)

d. Biological plausibility

Option-(d)

D)

b. Biological plausibility

Option-(b)