HLTH 2000 Chapter 7 Exam Questions With Revised Correct Detailed Answers Rated A+ Pass

HLTH 2000 Chapter 7 Exam Questions With Revised Correct Detailed Answers Rated A+ Pass Statistics - Answer- The term statistics refers to both the numbers that describe the health of the populations and the science that helps to interpret those numbers.The science of statistics is a set of concepts and methods used to analyze data in order to extract information. Statistics makes possible the translation of data into information about causes and effects, health risks, and disease cures. The Uncertainty of Science - Answer- In many cases, there are not enough data even to give us that degree of certainty, or the data that exist are too ambiguous to allow a valid conclusion. Contradictory results from epidemiologic studies are common. There are many possible sources of error in this kind of research, including bias and confounding, which are factors irrelevant to the hypothesis being tested that may affect a result or conclusion. Mammography Screening and the Uncertainty of Science - Answer- People sometimes demand certainty even when science cannot provide it, as occurred in 1997 over the issue of whether women ages 40 through 49 should be screened for breast cancer using mammography. When Dr. Richard Klausner, the director of the National Cancer Institute (NCI), called together a panel of experts in early 1997 to advise him on the issue, the panel concluded that, for younger women, the benefit did not justify the risks and costs, and recommended that each woman make the decision in consultation with her doctor, considering her own particular medical and family history. It seems clear that pressure from politicians eager to get credit for supporting women's health led to a pretense of scientific certainty where none existed. Remarkably, the whole political uproar was repeated in 2009, when an independent panel of experts, appointed by the Department of Health and Human Services, issued a recommendation that routine breast cancer screening begin at age 50, not 40. Probabilities - Answer- Scientists quantify uncertainty by measuring probabilities. Since all events, including all experimental results, can be influenced by chance, probabilities are used to describe the variety and frequency of past outcomes under similar conditions as a way of predicting what should happen in the future. False-Positives and False-Negatives - Answer- Studies with low power are likely to produce false-negative results (i.e., to find no effect when there actually is one). False-positive results occur when the study finds an effect that is not real. This common weakness in epidemiologic studies is probably one reason for the contradictory results so often reported in the news The Importance of Screening - Answer- When the causes of a disease are not well understood, little is known about primary prevention. The best public health measure is to screen the population at risk so as to detect the disease early, when it is most treatable. Screening: Sensitivity vs. Specificity - Answer- While laboratory tests to be used in screening programs should ideally be highly accurate, most are likely to yield either false positives or false negatives. Tests may be highly sensitive, meaning that they yield few false negatives, or they may be highly specific, meaning that they yield few false positives. Many highly sensitive tests are not very specific and vice versa. For most public health screening programs, sensitive tests are desirable in order to avoid missing any individual with a serious disease who could be helped by some intervention. However, inexpensive, sensitive tests chosen to encourage testing of as many at-risk individuals as possible are often not very specific. When a positive result is found, more specific tests are then conducted to determine if the first finding was accurate. Rates - Answer- Rates put the raw numbers into perspective by relating them to the size of the population being considered. Rates are usually calculated using the population at risk for the denominator. Death rates and birth rates are important rates that public health officials monitor.