Exam 5: Two-Way Tables

In a study of the link between high blood pressure (BP) and cardiovascular disease, a group of white males aged 35 to 64 was followed for five years. At the beginning of the study, each man had his blood pressure measured, and it was classified as either "low" systolic blood pressure (less than 140 mm Hg) or "high" blood pressure (140 mm Hg or higher). The following table gives the number of men in each blood pressure category and the number of deaths from cardiovascular disease during the five-year period: ? ? Deaths Total Low BP 10 2000 High BP 50 3500 Based on these data, which of the following statements is correct?

The following graph describes the percent of American adults aged 20 and older who used antidepressants in 2010, based on the 2010 America's State of Mind report. ​ ​ In 2010, approximately 32% of men older than age 20 years used antidepressants

A study in Sweden looked at former elite soccer players; people who had played soccer, but not at the elite level; and people of the same age who did not play soccer. Here is a two-way table that classifies these subjects based on whether they had arthritis of the hip or knee by their mid-fifties: ? ? Elite Non-elite Did not play Arthritis 10 9 24 No arthritis 61 206 548 Among the former elite soccer players, what proportion had arthritis of the hip or knee?

A study prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in 6294 men and women participating in the Sleep Heart Health Study. Study participants were classified into four groups depending on the extent of their sleep-disordered breathing (none, mild, moderate, or severe). The counts of deaths over the course of the study are reported for each group in the following two-way table: sleep-disordered breathing none mild moderate severe total death 476 320 165 86 1047 no death 2953 1477 562 255 5247 total 3429 1797 727 341 Based on this study, what can you conclude?

Obesity is a growing public health concern worldwide. Adults with a body mass index (BMI) of 25 or above are considered overweight or obese. The table below shows the number of adults (in millions) who are overweight or obese in countries with different income levels, based on data from the World Health Organization and the United Nation. ​ ​ Income level BMI \geq BMI < Total High 549 414 963 Upper middle 612 1042 1654 Lower middle 288 1083 1371 Low 63 357 420 All 1512 2896 4408 ​ -The majority of adults who are overweight or obese live in high-income countries. ?

Obesity is a growing public health concern worldwide. Adults with a body mass index (BMI) of 25 or above are considered overweight or obese. The table below shows the number of adults (in millions) who are overweight or obese in countries with different income levels, based on data from the World Health Organization and the United Nation. ​ ​ Income level BMI \geq BMI < Total High 549 414 963 Upper middle 612 1042 1654 Lower middle 288 1083 1371 Low 63 357 420 All 1512 2896 4408 ​ -What percent of adults who are overweight or obese live in low-income countries? ​

The following graph describes the percent of American adults aged 20 and older who used antidepressants in 2010, based on the 2010 America's State of Mind report. ​ ​ In 2010, approximately 32% of adults older than age 20 years who used antidepressants were men.

A survey was designed to study how brook trout populations respond to various levels of urbanization. Urbanization had three levels: low, medium, and high impact. Historical habitats for brook trout were observed, with 200 habitats randomly selected within each level of urbanization, for a total of 600 habitats. Researchers marked each population as extirpated or present. The data are given in the following two-way table. ? ? Extirpated Present Total Low impact 25 175 200 Medium impact 80 120 200 High impact 195 5 200 What percent of habitats subject to high levels of urbanization were found to be present?

Chronic fatigue syndrome (CFS) is a debilitating disease of unknown etiology that is estimated to affect 17 million people worldwide. Studying peripheral blood mononuclear cells from patients with CFS, researchers identified DNA from a human gamma-retrovirus (XMRV) in 68 of 101 patients, compared with 8 of 218 healthy controls. What may we conclude from these data?

The following graph describes the percent of American adults aged 20 and older who used antidepressants in 2010, based on the 2010 America's State of Mind report. ​ ​ In 2010, men across all three age groups had a substantially higher rate of antidepressant use than women.

Chronic fatigue syndrome (CFS) is a debilitating disease of unknown etiology that is estimated to affect 17 million people worldwide. Studying peripheral blood mononuclear cells from patients with CFS, researchers identified DNA from a human gamma-retrovirus (XMRV) in 68 of 101 patients, compared with 8 of 218 healthy controls. What percent of the CFS patients were found to have XMRV DNA?

A study prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in 6294 men and women participating in the Sleep Heart Health Study. Study participants were classified into four groups depending on the extent of their sleep-disordered breathing (none, mild, moderate, or severe). The counts of deaths over the course of the study are reported for each group in the following two-way table: sleep-disordered breathing none mild moderate severe total death 476 320 165 86 1047 no death 2953 1477 562 255 5247 total 3429 1797 727 341 What is the best comparison group for the proportion of people who died among those with no sleep-disordered breathing?

A study prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in 6294 men and women participating in the Sleep Heart Health Study. Study participants were classified into four groups depending on the extent of their sleep-disordered breathing (none, mild, moderate, or severe). The counts of deaths over the course of the study are reported for each group in the following two-way table: sleep-disordered breathing none mild moderate severe total death 476 320 165 86 1047 no death 2953 1477 562 255 5247 total 3429 1797 727 341 What is the overall proportion of subjects who died of any cause during the study?

Chronic fatigue syndrome (CFS) is a debilitating disease of unknown etiology that is estimated to affect 17 million people worldwide. Studying peripheral blood mononuclear cells from patients with CFS, researchers identified DNA from a human gamma-retrovirus (XMRV) in 68 of 101 patients, compared with 8 of 218 healthy controls. What percent of individuals in the study were found to have XMRV DNA?

A survey was designed to study how brook trout populations respond to various levels of urbanization. Urbanization had three levels: low, medium, and high impact. Historical habitats for brook trout were observed, with 200 habitats randomly selected within each level of urbanization, for a total of 600 habitats. Researchers marked each population as extirpated or present. The data are given in the following two-way table. ? ? Extirpated Present Total Low impact 25 175 200 Medium impact 80 120 200 High impact 195 5 200 Which of the following conclusions seems to be supported by the data?