# Explain The Five Steps To Describe Baye Theorem And Alternative To Bayes Theorem

1459 Words6 Pages
Lauren Berman Chapter 8 – Biostatistics Data 1.) Describe Bayes theorem and alternative to Bayes theorem. Bayes theorem is used to answer two different questions, “If the test results are positive, what is the probability that the patient has the disease?” and “If the test results are negative, what is the probability that the patient does not have the disease” (93). In the formula for Bayes theorem, the numerator is the true positive results and the denominator tells about true positive results and false positive results. An alternative to Bayes theorem is used in genetics (94). 2.) Explain the five steps to setting up a decision tree. There are five steps involved in creating a decision tree. The first step is to identify and set limits to the problem, for example whether or not the gallbladder of a person without symptoms should be removed. The second step is to diagram the options. This can be done by starting with the patient’s current clinical status, then laying out the different options and the outcomes that could come from each option. The third step is to obtain information on each option. In this step, the possibility of each outcome occurring should be assessed and then the outcomes should be separated into desirable and undesirable outcomes. The fourth step is to compare utility values and the fifth step is to perform sensitivity analysis (97-98). 3.) Define the two different types of meta-analysis. A qualitative meta-analysis is “a systemic review of the literature on a particular topic” (99). Different articles on the same topic are reviewed and the results, strengths, and weaknesses of each article are assessed. A quantitative meta-analysis can be presented in two ways, either “the data are analyzed as reported in the literature, or the raw data from multiple studies are obtained and aggregated” (100). 4.) Explain the difference between independence rule, product rule, and addition rule. The independence rule says that “one probability is not influenced by the outcome of another probability” (101). In this situation, if the two probabilities are independent of each other, then the trial can be repeated twice in a row and multiple times. The product rule is “used to determine the