SAR HS300 Epidemiology

Assignment 1

1. There are 56,472 people living with stomach cancer in the United States as of 2020. Inclusive of those cases, 22,425 were newly diagnosed cases of stomach cancer and 11,233 stomach cancer deaths were recorded in the United States. The estimated population of the United States in 2020 is 329.5 million. (15 points)

a. Calculate the prevalence of stomach cancer per 100,000 population in the United States in 2020 (report result to 2 decimal places) (5 points)

56472 / 329500000 * 100000 = 17.14

b. Calculate the incidence of stomach cancer per 100,000 population in the United States in 2020 (report result to 2 decimal places) (5 points)

22425 / 329500000 * 100000 = 6.81

c. Calculate the mortality rate from stomach cancer per 100,000 population in the United States in 2020 (report result to 2 decimal places) (5 points)

11233 / 329500000 * 100000 = 3.41

2. In January 2010, a team of epidemiologists recruited 100,000 persons in Peru, 18-35 years of age, for a 10-year study on tuberculosis (TB) incidence. Tests conducted at the study outset indicated that 5,840 persons in this study’s initial sample already had TB. Eligible study subjects were then followed prospectively for ten years to determine the cumulative incidence rate of TB in this study sample. By the end of the ten years of follow-up 1,473 subjects had developed TB. (15 points)

a. What was the ten-year (cumulative) incidence rate of TB (per 100,000) in this study? (report result to 2 decimal places) (10 points)

1473 / (100000 - 5840) * 100000 = 1564.36

b. Interpret your results in a statement (i.e. a full sentence). (5 points)

In 10-year study on the risk of tuberculosis among 18 to 35 years of age at the study onset, the incidence rate of tuberculosis was 1564.36 per 100000.

3. A population of 9,658 people, aged 45 – 70 years who were breast cancer cancer-free were selected and followed for the development of breast cancer over a ten-year study period. 27 subjects were followed for one year and then were lost to follow-up. In year two, 5 subjects developed breast cancer and 20 subjects were lost to follow-up. In year three, 8 subjects developed breast cancer and 28 were lost to follow up. During year six, 23 subjects developed breast cancer and 35 were lost to follow up. In year eight, 22 subjects developed breast cancer and 102 were lost to follow up.  In year nine, 17 subjects developed breast cancer. In year ten, 29 subjects developed breast cancer. The remaining subjects did not have breast cancer and were followed for the entire ten years. (25 points)

a.      Develop a table and calculate the number of person-years accrued among this study population (10 points)

9658 - 316 = 9342 → 9342 * 10 = 93420 person-years

Total person-years = 93420 + 1968 = 95388 person-years

b.     Calculate the breast cancer incidence rate per 100,000 person-years (report result to 2 decimal places) (10 points)

New cases = 5 + 8 + 23 + 22 +17 + 29 = 104

Incidence rate = 104 / 95388 * 100000 = 109.03 per 100000 person-years

c. Interpret your result in a statement (i.e. a full sentence) (5 points)

In a 10-year longitudinal study on breast cancer among adults aged 45 to 70 years at study outset, the incidence rate of breast cancer was 109.03 per 100000 person-years.

4. The California Department of Public Health reported that there were 12,090 cases of RSV infection requiring hospitalization in California (population of 39 million) in the 2022-2023 flu season. On February 1st, 2022, 156 of those cases were hospitalized. What was the prevalence rate per 100,000 of flu hospitalizations in California:

a. On February 1^st? Identify the prevalence type in your response. Report result to 2 decimal places (5 points)

This represents point prevalence, as it refers to the number of cases on specific time (February 1st, 2022)

156 / 39000000 * 100000 = 0.4

The prevalence rate per 100,000 on February 1st, 2022 is 0.40

b. In the 2022-2023 flu season? Identify the prevalence type in your response. (Report result to 2 decimal places (5 points)

This represents period prevalence, as it refers to the total number of cases during the entire flu season.

12090 / 39000000 * 100000 = 31

The prevalence rate per 100000 in the 2022-2023 flu season is 31

5. Using the data in Table 1 (below), from The Massachusetts Department of Public Health

a. Calculate to 2 decimal points the Covid incidence per 100,000 per month from January through December 2022 to complete the table (10 points)

b. Create a line graph showing the MA Covid rate per month from January – Dec 2022. Your graph must include the following: title (to include topic, dates and source of data), correctly labeled X and Y axes. No hand drawn graphs please (15 points)

c. From the data provided, calculate the COVID cumulative incidence rate in Massachusetts in 2022 (10 points)

428319 + 57722 + 32054 + 63147 + 106341 + 60410 + 44670 + 37751 +47042 + 32434 + 32041 + 43565 = 985496

Cumulative incidence rate = 985496 / 698100 * 100000 = 141168.31

Table 1. New COVID cases by Month in MA, 2022 (Total Population = 6,981,000)

Total