Exam 3: The Phoenix of Statistics

A researcher presented a recent study, which showed a statistical significance between increased consumption of sugar and increased tests scores in young children. How can she explain to the chief medical officer that advertising the importance of increasing sugar in children's diets should not be broadcast in the media?

A researcher was assessing patient healing time when using a new form of surgical dressing called MediDressX. He had a sample size of 48 and a p-value of 0.20. Does the researcher recommend that hospitals stop using this product?

A trainee data analyst for a large hospital, which has higher than average patient mortality rates, has just completed an examination of key factors that may be influencing these high mortality rates. However, he finds only one statistically significant factor, which he includes in his report but deliberately, omits the other six non-significant findings. What is the term for what the data analyst has done?

Your head of clinical practice has just read a book on criticisms of the NHST and worries that all clinical data analysis is now flawed. How might you reassure her?

A researcher was interested in patient use of pop-up Flu vaccine clinics across thirty sites nationally. Different researchers collected and analysed data across each of the sites but the resultant thirty reports showed differing p-values, some sites found a statistical significance between opening hours of clinics and patient usage and others did not. Which of the following would is useful for her to review?

A person involved in health promotion wanted to examine the likelihood that health promotion messages on social media would be more effective than in print media. She conducted one study where the probability of making a Type I error was 0.05 and a Type II error was 0.2. Does her research have empirical probability?

Your health research lecturer has devoted the past ten weeks to teaching you the Bayesian approach and is now asking that you offer a critique of it. What key criticism could you raise?

Your head of clinical practice has followed your advice and now wants you to measure effect sizes. You report a Pearson's r of 0.50 for the impact of increased consumption of oily fish supplements on the symptoms of dementia. Your head of clinical practice wants to know if this is bad, as she remembers that a p-value of 0.30 is not good. What do you tell her?

You lead a product-testing unit for a large pharmaceutical company. Your team has conducted forty trials of a new antibiotic but you are not sure if the results are conclusive enough to urge the company to start producing the new drug. A new data analyst has joined your team suggesting that meta-analysis might be a good idea, do you agree?

Which of the following is not a factor in researchers' over-use of p-values and NHST in health research?

A midwife conducted a Bayesian analysis of stork numbers and declining birth rates. She calculated a Bayes factor of 1. Should she use stork numbers to predict birth rates?

A researcher was interested in assessing gender and response to pain, so conducted a t-test. The mean for males was 66.25 and the mean for females was 78.24, with both groups having a standard deviation of 7. What is the effect size using Cohen's d?

In our previous example, the doctor had already calculated the probability of patient life expectancy based on national cancer data. In a Bayesian approach, what sort of probability is this?

A doctor is concerned about the life expectancy rates of cancer patients in his clinic. There were forty patients in the clinic all of whom were in remission from cancer. Theoretically, all the patients had an equal probability of living for at least ten years post-treatment. However, the doctor had data that suggested that younger patients were more likely to live longer than older patients. This data was from national cancer data. However, the doctor had used the same and newly developed approach to treatment for all his patients and therefore wanted to determine the probability that all patients would live for at least ten years post-treatment, irrespective of their age. What formula could he use to determine this probability?

You are the head of a large medical group. You have decided to adopt a Bayesian approach to data analysis and modelling. When you announce this new policy, your staff are unhappy and unconvinced, as they are used to a NHST approach. You stress that the Bayesian approach has several key advantages, including which of the following.

You have joined the data modelling team for a health policy unit. Your boss has decided that from now on the team will adopt a Bayesian approach. However, not all staff understand what this is; your boss asks you to present a training session. How would you explain s Bayesian appaorch in your session introduction?