Biostatistics Assignment Questions

Instructions: Please copy/paste your individual answers and work to this document. You may use extra space when necessary.

Question 1) The infant mortality rate for Pennsylvania (PA) for the 1983-1985 period was 10.9 per 100 live births compared to 12.5 for Louisiana (LA). In your own words, is it appropriate to conclude that PA had a better record than LA related to infant mortality? The infant mortality rate for whites in PA was 9.4 and was 20.9 for blacks. This is in contrast with the rates 9.1 and 18.1 for whites and blacks respectively, in LA (National Center for Health Statistics 1987). Hence the race specific rates were lower in LA than in PA, but the overall rate was higher in LA. Based on those items that you should consider when interpreting studies, explain how you think this situation could arise. (This question is best answered after reviewing course content from week 1)

Question 2-3)Create a bar chart for the data on serum Cholesterol for non-Hispanic whites, based on the data table provided below. A high value of serum cholesterol is thought to be a risk factor for heart disease. The National Cholesterol Education Program of the National Institutes of Health in 1987 stated that the recommended value for serum cholesterol is below 200, and a value above 240 may indicate a problem, and recommended a that a lipoprotein analysis should be performed. Based on these data, it appears that many non-Hispanic whites have serum cholesterol values that are too high, particularly women. The medical literature is also finally beginning to recognize that homocysteine is a very important risk factor for heart disease, even in people with normal serum cholesterol. Give some possible reasons why non-Hispanic white males have higher mortality from heart and cerebrovascular diseases when it appears from these data that non-Hispanic white females should have higher rates. (This question is best answered after reviewing course content from week 1 and Excel Tutorial Part 1).

Question 4-5)Use line graphs to represent the short –stay hospital rates shown; and discuss trends, if any, in these data. (This question is best answered after reviewing course content from week 1)

Hospital Ownership (Source: NCHS, 1992)

Year

Federal

Nonprofit

Proprietary

State/Local

1960

82.5

76.6

65.4

71.6

1970

77.5

80.1

72.2

73.2

1975

77.6

77.4

65.9

69.7

1980

77.8

78.2

65.2

70.7

1985

74.3

67.2

52.1

62.8

1989

71.0

68.8

51.7

64.8

Question 6-7) Lee (1980) presented survival times in months from diagnosis for 70 patients with either acute myeloblastic leukemia (AML) or acute lymphoblastic leukemia (ALL). Calculate the sample mean ad median for both AML and ALL patients separately. Which measure do you believe is more appropriate to use with these data? Explain. (This question is best answered after reviewing course content from week 1).

Question 8) Based on the data from the Hispanic Health and Nutrition Examination Survey (HHANES) (LSRO 1989), the mean serum cholesterol for Mexican-American males age 20-74 was 203. The standard deviation was approximately 44mg/dL. Assume the serum cholesterol follows a normal distribution. What is the probability that a Mexican- American male 20-74 has a serum cholesterol value greater than 240? (This question is best answered after reviewing course content from week 2)

Question 9) the mean endurance time for a sample of 36 girls 4-5 years old was 9.5 minutes with a standard deviation of 1.86 minutes. If we assume that these are the true population mean and standard deviation, and if we also assume that the endurance time follows a normal distribution, what is the probability of observing 4 year old girl with an endurance of 7 minutes? Is the data set normally distributed? Explain your answer. (This question is best answered after reviewing course content from week 2)

Question 10) Calculate the mean state proportion of those without health insurance from data in the table below. Is this number the same as the overall US percentage? Explain how the state information can be used to obtain the overall US percentages of 14.1. (This question is best answered after reviewing course content from weeks 1-3).