A researcher is investigating whether there is an association between the use of social media in teenagers and bipolar disorder. In order to study this potential relationship, she collects data from people who have bipolar disorder and matched controls without the disorder. She then asks how much on average these individuals used social media in the 3 years prior to their diagnosis. This continuous data is divided into 2 groups: those who used more than 2 hours per day and those who used less than 2 hours per day. She finds that out of 1000 subjects, 500 had bipolar disorder of which 300 used social media more than 2 hours per day. She also finds that 400 subjects who did not have the disorder also did not use social media more than 2 hours per day. Which of the following is the odds ratio for development of bipolar disorder after being exposed to more social media?
A1.5
B6
C0.17
D0.67
A randomized control double-blind study is conducted on the efficacy of 2 sulfonylureas. The study concluded that medication 1 was more efficacious in lowering fasting blood glucose than medication 2 (p ≤ 0.05; 95% CI: 14 [10-21]). Which of the following is true regarding a 95% confidence interval (CI)?
AIf the same study were repeated multiple times, approximately 95% of the calculated confidence intervals would contain the true population parameter.
BThe 95% confidence interval is the probability chosen by the researcher to be the threshold of statistical significance.
CWhen a 95% CI for the estimated difference between groups contains the value ‘0’, the results are significant.
DIt represents the probability that chance would not produce the difference shown, 95% of the time.
EThe study is adequately powered at the 95% confidence interval.
An investigator for a nationally representative health survey is evaluating the heights and weights of men and women aged 18–74 years in the United States. The investigator finds that for each sex, the distribution of heights is well-fitted by a normal distribution. The distribution of weight is not normally distributed. Results are shown: Mean Standard deviation Height (inches), men 69 0.1 Height (inches), women 64 0.1 Weight (pounds), men 182 1.0 Weight (pounds), women 154 1.0 Based on these results, which of the following statements is most likely to be correct?
A86% of heights in women are likely to fall between 63.9 and 64.1 inches.
B99.7% of heights in women are likely to fall between 63.7 and 64.3 inches.
C68% of weights in women are likely to fall between 153 and 155 pounds.
D95% of heights in men are likely to fall between 68.85 and 69.15 inches.
E99.7% of heights in men are likely to fall between 68.8 and 69.2 inches.
+ 7 more in the PDF
Browse all chapters