Measuring Associations

Epidemiological measures of effect assess the _______ between an exposure and an outcome.

• strength of the causal mechanisms

• strength of the reversibility

• strength of the association

• strength of a confounding factor

In which one of the following circumstances will the prevalence of a disease in the population increase, all else being constant?

• If the incidence rate of the disease falls.

• If survival time with the disease increases

• If recovery of the disease is faster.

• If the population in which the disease is measured

In a cohort study, the risk ratio of developing diabetes was 0.86 when comparing consumers of tea (the exposed) to those who did not drink tea (the unexposed). Which one statement is correct?

• The tea drinkers have lower risk of developing diabetes.

• The tea drinkers have higher risk of developing diabetes.

• Based on the information given we cannot tell if the observed difference in disease risk is the result of chance.

• The risk ratio is close to the value one, so there is no difference in disease risk between the two groups.

The coefficient of correlation

• is the square of the coefficient of determination

• is the square root of the coefficient of determination

• is the same as r-square

• a.can never be negative

When data are of ordinal level (ranked date), in this case ____________ can be used to determine the degree of association between the variables

• Pearson correlation

• Durbin-Watson statistic

• Spearman’s rank correlation

• Factorial design