A new test to screen for heart disease is used in 100 patients who present to the Cardiology Clinic. The test is positive in 30 of the 40 patients who are proven to have heart disease. Of the remaining 60 patients, only 5 have a positive test. What is the sensitivity of the new test?
A study is conducted to evaluate the effectiveness of a new medication for treating high cholesterol. Two groups of patients are randomly assigned, one group taking the established drug for 6 months and the other taking the new drug for 6 months. Cholesterol levels are measured before and after the treatment. After a one-month break from medication, the groups switch medications and cholesterol levels are measured again. The difference in cholesterol levels before and after each medication is calculated for each patient. Which statistical test is most suitable for analyzing the results?
A recently published meta-analysis on the prevalence of interstitial lung disease in elderly patients with a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is discussed at a geriatric medicine conference that you attend. The speaker suggests that there may be a publication bias affecting the results.
What statistical method, graph or examination would be the most effective in exploring the speaker’s hypothesis?
A test that seems to assess its intended purpose upon initial examination is referred to as having which of the following qualities?
A 62-year-old man, whose wife had a TIA one month ago, shows you a newspaper article titled ‘new super drug prevents stroke’. As you read through the article together, it states that a recent clinical trial has revealed a lipid-lowering therapy for stroke with a number needed to treat (NNT) of 20 for the prevention of the primary end-point. How would you explain these findings to him?
A 45-year-old woman has been diagnosed with breast cancer after a lesion was detected during a routine mammogram as part of the NHS Breast Screening program. What are the optimal features of a screening test?
A study is designed to compare the cholesterol levels of males and females who have hypertension. The researchers aim to determine if there is a significant difference between the mean cholesterol level in males and females. It is known from previous studies that the cholesterol levels follow a normal distribution. Which statistical test would be the most suitable to use?
Which of the following is a form of qualitative research that depicts the customs of a community?
When two medical conditions are related through the presence of a confounding factor, the association is said to be:
A clinical trial is being conducted to assess the effectiveness of a new drug in reducing blood pressure in patients with hypertension. The null hypothesis states there is no difference between the new drug and placebo in reducing blood pressure.
After collecting the appropriate data, statistical analyses are conducted and the researcher wants to quantify if the observed difference may have occurred just by chance. He calculates this probability assuming the null hypothesis is correct.
What is this known as?