Essentials of Biostatistics and Public Health Chapter 4&5 Review Questions and Correct Answers Latest Update 2024 (Rated A+)

Essentials of Biostatistics and Public Health Chapter 4&5 Review Questions and Correct Answers Latest Update 2024 (Rated A+) Distinguish between dichotomous, ordinal, continuous, and categorical variables. - Answers •Dichotomous variables have 2 possible responses (e.g., Yes/No) •Ordinal AND Categorical variables have more than two responses and responses are ordered for ordinal variables and unordered for categorical variables. •Continuous (or measurement) variables assume in theory any values between a theoretical minimum and maximum What Are the Two Areas of Applied Biostatistics? - Answers Descriptive Statistics -Summarize a sample selected from a population Inferential Statistics -Make inferences about population parameters based on sample statistics. What is a statistic? What is a parameter? - Answers •Any summary measure computed on a SAMPLE is a Statistic •Any summary measure computed on a POPULATION is a Parameter T/F: N = population size. n = sample size - Answers True Label and explain the five points of a box and whisker plot. - Answers Min Q1 Median Q3 Max. Min = Q1 = First quartile holds approximately 25% of the scores at or below it Median = a value or quantity lying at the midpoint of the values, such that there is an equal probability of falling above or below it. Q3 = Third quartile holds approx. 25% of the scores at or above it Max = What is the first step in a Biostatistical Analysis? (After selecting a sample). What is the next step in a Biostatistical Analysis - Answers Once a sample is selected, THE CHARACTERISTIC OF INTEREST MUST BE SUMMARIZED IN THE SAMPLE USING APPROPRIATE TECHNIQUES. This is the first step in an analysis. Once the sample is appropriately summarized, STATISTICAL INFERENCE PROCEDURES ARE THEN USED TO GENERATE INFERENCES ABOUT THE POPULATION BASED ON THE SAMPLE. What do the appropriate biostatistical numerical summaries and graphical displays depend on? - Answers The type of characteristic understudy. Characteristics (sometimes called variables, outcomes, or endpoints) are classified as one of the following types: dichotomous, ordinal, categorical, or continuous. Name and describe each of the 4 classifications for biostatistic information (AKA characteristics or variables or outcomes or endpoints). - Answers 1. DICHOTOMOUS VARIABLES have only two possible responses. The response options are usually coded "yes" or "no:' Exposure to a particular risk factor (e.g., smoking) is an example of a dichotomous variable. 2.ORDINAL & CATEGORICAL VARIABLES have more than two possible responses but the response options are ordered and unordered, respectively. Symptom severity is an example of an ordinal variable with possible responses of minimal, moderate, and severe. 3. CATEGORICAL variables, sometimes called NOMINAL variables, are similar to ordinal variables except that the responses are unordered. Race/ ethnicity is an example of a categorical variable. It is often measured using the following response options: white, black, Hispanic, American Indian or Alaskan native, Asian or Pacific Islander, or other. 4. CONTINUOUS VARIABLES, SOMETIMES CALLED QUANTITATIVE OR MEASUREMENT VARIABLES, in theory take on an unlimited number of responses between defined minimum and maximum values. Systolic blood pressure, diastolic blood pressure, total cholesterol level, CD4 cell count, platelet count, age, height, and weight are all examples of continuous variables. For example, systolic blood pressure is measured in millimeters of mercury (mmHg), and an individual in a study could have a systolic blood pressure of 120, 120.2, or 120.23, depending on the precision of the instrument used to measure systolic blood pressure. Multiple measurements taken on the same individual are referred to as ____ measures data. - Answers Clustered or repeated Prevalent disease status, where each individual in a sample is classified as having or not having the disease of interest at a point in time, is an example of what type of characteristic classification? - Answers Dichotomous ___ reflects the number of independent or distinct units (participants) in a sample. - Answers Sample size (n) The National Heart, Lung, and Blood Institute (NHLBI) issues guidelines to classify blood pressure as normal, pre-hypertension, Stage I hypertension, or Stage II hypertension. The classification scheme is based on specific levels of systolic blood pressure (SEP) and diastolic blood pressure (DBP). Participants are classified into the highest category, as defined by their SBP and DBP. Blood pressure category is a(n) ____ variable. - Answers Ordinal