need help with 20, 22, 23, 24, 27
Suppose you were doing a study on whether coffee drinking Increased the risk of heart disease (see Exhibit B.4). Assume that you heart disease. You had two group of 110 subjects, each whom you to are no longer at risk of heart disease if you die, leave the study of Capstone Cases 554 AVIO ANA QUESTIS 14. Wha per 15. Wh lowed for five years. 16. He dr n110 Coffee Drinkers 17. He CE Group 1 4 5 3 Risk 2 EXHIBIT 8.4 Coffee Drinking and Heart Disease Study Disease 18. 90 Left 19. 5 Died 5 20. 5 5 21. n = 110 Group 2 22 Non-Coffee Drinkers 4 2 3 1 5 100 2 2 3 3 Group 1 (the coffee drinkers): 90 followed for 5 years without get- ting heart disease, 5 each get heart disease at the end of years 3 and 4, respectively, 5 leave the study at the end of year 2, and 5 die at the end of year 4. Group 2 (non-coffee drinkers): 100 followed for 5 years without getting heart disease, 2 each get heart disease at the end of years 1 and 2, respectively, 3 leave the study at the end of year 4. 3 die at the end of year 3. (continued from previous page) 14. What is the cumulative five-year incidence rate express as HD patients) for coffee drinkers? 18. What is the incidence density rate (express as HD per 100 patient-years) for coffee drinkers? 23. For incidence rates, the population at risk should exclude cases with the disease (who are no longer at risk of contracting the What is the cumulative five-year incidence rate (express as HD 16. How many patient years of being at risk do we have for coffee Capstone Cases 555 QUESTIONS per 100 15 patients) for non-coffee drinkers? per 100 drinkers? How many patient years of being at risk do we have for non- 10. What is the incidence density rate (express as #HD per 100 patient-years) for non-coffee drinkers? zo. Using cumulative incidence, how many times more likely are coffee drinkers to get heart disease than non-coffee drinkers? 21. Using cumulative density, how many times more likely are coffee drinkers to get heart disease than non-coffee drinkers? 22. Assume that Exhibit B.s reports the number of US residents age 45 and older by race and gender with prevalent or incident congestive heart failure. Use Exhibit B.1 to get the denominator and calculate the prevalent and incident rates for each category. What is the relationship between prevalence and incidence? Can you calculate the average duration with the disease for each group? What is the ratio of prevalence to incidence rates for each group? Number of US Residents (in thousands) White White Black Black Males Females Males Females 421 EXHIBIT B.5 Number of US Residents (in Thousands) with Prevalent or incident Congestive Heart Failure (CHF), Age 45 and Older 511 1,439 1,783 40 Prevalent CHF 44 232 253 Incident CHF (continued disease). Let us assume that the number of US residents with existing congestive heart failure (CHF) on December 31, 2009. was 4.780,000 for white males, 1,440,000 for white females. 515.000 dence rates for the four categories. What happened to the rates? for black males, and 418,ooo for black females. Calculate new idi 24. Suppose that you are able to get data on incident and prevalent million prevalent cases and 250.000 incident cases. You do not cases of white males aged 45 and older with CHF for 2011-1.75 have the size of the 45 and older white male population for 2011; however you do know that there were 48.4 million on January prevalent cases of CHF Furthermore, in 2010 there were 3-4 1, 2010, and on December 31, 2010, there were 1.8 million point million white males who were 44 years old in 2010 and 2.5 million white males aged 44 and older who died during 2010. What would be the size of the denominators for prevalent and incident rates in 2011? What would the 2011 CHF incidence and prevalence rates numerators and denominators and apply to a specific time period, 10.000 W 556 Capstone Cases day) metabolic syn CVD among m mhose without those with MS QUESTIONS 26. What is women meta-a do you 27. What versus Thank yo contribut (per 1,000) be? 25. Both prevalence and incidence rates are calculated from disease (CVD). Suppose that you did a large study of 10,000 men and Incidence and prevalence rates can also be used to compare the rates of disease across different settings (places), people, or time. We therefore need measures of comparison. The ratio of two measures of disease frequency is called the relative risk. The difference between two measures of disease frequency is called the risk difference, or rate difference. In some cases, it involves a measure in an exposed group (or groups) and a measure in an unexposed or comparison group. In other cases, it may not-for example, you may want to compare CHF rates among blacks versus whites, as we did earlier. Metabolic syndrome (MS), also called insulin resistance syndrome, is associated with cardiovascular disease and is defined by the pres- ence of at least three of the following risk factors: high plasma glu- cose, low high-density lipoproteins (HDL), high triglycerides, a large waist circumference, and high blood pressure. A meta-analysis (Gami et al. 2007) that combined 37 separate studies showed that MS puts both men and women at increased risk of developing cardiovascular Accuracy for the numerators and denominators is critical. Please identify the measurement issues associated with numerators, denominators, and time period. Suppose you were doing a study on whether coffee drinking Increased the risk of heart disease (see Exhibit B.4). Assume that you heart disease. You had two group of 110 subjects, each whom you to are no longer at risk of heart disease if you die, leave the study of Capstone Cases 554 AVIO ANA QUESTIS 14. Wha per 15. Wh lowed for five years. 16. He dr n110 Coffee Drinkers 17. He CE Group 1 4 5 3 Risk 2 EXHIBIT 8.4 Coffee Drinking and Heart Disease Study Disease 18. 90 Left 19. 5 Died 5 20. 5 5 21. n = 110 Group 2 22 Non-Coffee Drinkers 4 2 3 1 5 100 2 2 3 3 Group 1 (the coffee drinkers): 90 followed for 5 years without get- ting heart disease, 5 each get heart disease at the end of years 3 and 4, respectively, 5 leave the study at the end of year 2, and 5 die at the end of year 4. Group 2 (non-coffee drinkers): 100 followed for 5 years without getting heart disease, 2 each get heart disease at the end of years 1 and 2, respectively, 3 leave the study at the end of year 4. 3 die at the end of year 3. (continued from previous page) 14. What is the cumulative five-year incidence rate express as HD patients) for coffee drinkers? 18. What is the incidence density rate (express as HD per 100 patient-years) for coffee drinkers? 23. For incidence rates, the population at risk should exclude cases with the disease (who are no longer at risk of contracting the What is the cumulative five-year incidence rate (express as HD 16. How many patient years of being at risk do we have for coffee Capstone Cases 555 QUESTIONS per 100 15 patients) for non-coffee drinkers? per 100 drinkers? How many patient years of being at risk do we have for non- 10. What is the incidence density rate (express as #HD per 100 patient-years) for non-coffee drinkers? zo. Using cumulative incidence, how many times more likely are coffee drinkers to get heart disease than non-coffee drinkers? 21. Using cumulative density, how many times more likely are coffee drinkers to get heart disease than non-coffee drinkers? 22. Assume that Exhibit B.s reports the number of US residents age 45 and older by race and gender with prevalent or incident congestive heart failure. Use Exhibit B.1 to get the denominator and calculate the prevalent and incident rates for each category. What is the relationship between prevalence and incidence? Can you calculate the average duration with the disease for each group? What is the ratio of prevalence to incidence rates for each group? Number of US Residents (in thousands) White White Black Black Males Females Males Females 421 EXHIBIT B.5 Number of US Residents (in Thousands) with Prevalent or incident Congestive Heart Failure (CHF), Age 45 and Older 511 1,439 1,783 40 Prevalent CHF 44 232 253 Incident CHF (continued disease). Let us assume that the number of US residents with existing congestive heart failure (CHF) on December 31, 2009. was 4.780,000 for white males, 1,440,000 for white females. 515.000 dence rates for the four categories. What happened to the rates? for black males, and 418,ooo for black females. Calculate new idi 24. Suppose that you are able to get data on incident and prevalent million prevalent cases and 250.000 incident cases. You do not cases of white males aged 45 and older with CHF for 2011-1.75 have the size of the 45 and older white male population for 2011; however you do know that there were 48.4 million on January prevalent cases of CHF Furthermore, in 2010 there were 3-4 1, 2010, and on December 31, 2010, there were 1.8 million point million white males who were 44 years old in 2010 and 2.5 million white males aged 44 and older who died during 2010. What would be the size of the denominators for prevalent and incident rates in 2011? What would the 2011 CHF incidence and prevalence rates numerators and denominators and apply to a specific time period, 10.000 W 556 Capstone Cases day) metabolic syn CVD among m mhose without those with MS QUESTIONS 26. What is women meta-a do you 27. What versus Thank yo contribut (per 1,000) be? 25. Both prevalence and incidence rates are calculated from disease (CVD). Suppose that you did a large study of 10,000 men and Incidence and prevalence rates can also be used to compare the rates of disease across different settings (places), people, or time. We therefore need measures of comparison. The ratio of two measures of disease frequency is called the relative risk. The difference between two measures of disease frequency is called the risk difference, or rate difference. In some cases, it involves a measure in an exposed group (or groups) and a measure in an unexposed or comparison group. In other cases, it may not-for example, you may want to compare CHF rates among blacks versus whites, as we did earlier. Metabolic syndrome (MS), also called insulin resistance syndrome, is associated with cardiovascular disease and is defined by the pres- ence of at least three of the following risk factors: high plasma glu- cose, low high-density lipoproteins (HDL), high triglycerides, a large waist circumference, and high blood pressure. A meta-analysis (Gami et al. 2007) that combined 37 separate studies showed that MS puts both men and women at increased risk of developing cardiovascular Accuracy for the numerators and denominators is critical. Please identify the measurement issues associated with numerators, denominators, and time period
