Question

For each of the following, provide whether the confidence intervals (CI) lead to a conclusion of statistically significant difference or not? Provide your reasoning.
A CI of (-0.01, 0.03) for difference in proportions of smokers compared to nonsmokers with prevalent CVD.
A CI of (0.2, 0.3) for difference in proportions of smokers compared to nonsmokers with prevalent disease (some disease of interest).
A CI of (0.89, 1.41) for relative risk of prevalent CVD in smokers as compared to nonsmokers.
A CI of (1.19, 1.41) for relative risk of prevalent disease (some disease of interest) in smokers as compared to nonsmokers.

Answer 1

#1.
CI of (-0.01, 0.03) includes 0, hence we reject the null hypothesis.
Conclusion: There is no statistically significant difference.

#2.
CI of (0.2, 0.3) does not include 0, hence we reject H0.
Conclusion: There is statistically significant difference.

#3.
CI of (0.89, 1.41) does not include 0, hence we reject H0.
Conclusion: There is statistically significant difference.

#4.
CI of (1.19, 1.41) does not include 0, hence we reject H0.
Conclusion: There is statistically significant difference.