Reference no: EM132281549

Epidemiology and Biostatistics Assignment Questions -

Q1. Read the following and answer the questions below.

The following is extracted (and edited) from: Pirkis, J. et al. (2017) 'Masculinity and suicidal thinking', Social Psychiatry and Psychiatric Epidemiology, 52(3), pp. 319-327.

Purpose - Males feature prominently in suicide statistics, but relatively little work has been done to date to explore whether endorsement of dominant masculinity norms heightens the risk of or is protective against suicidal thinking. This paper aimed to [gain] further knowledge in this area.

Methods - We used data from the 13,884 18-55 year old men who participated in the baseline wave (Wave 1) of Ten to Men to investigate the relationship masculinity and suicidality. [...] The Ten to Men cohort was recruited in 2013/14 using a stratified, multi-stage, cluster random sampling strategy in which the primary unit of sampling was the household. We approached all 104,884 households in 622 randomly selected statistical areas (SA1 s, which have boundaries defined by the Australian Bureau of Statistics and average populations of about 400 individuals). We were able to make contact with 81,400 (78%) of these households and 33,724 (32%) were identified as having at least one in-scope resident (a male aged between 10 and 55). We identified 45,510 in scope males in these households, and 15,988 (35%) of these returned useable data, providing representation from all Australian states and territories and from major cities and inner and outer regional areas. The response fraction [response rate] for the restricted age range considered in the current paper (18-55 years) was 36%.

Results - After controlling for other key predictors of suicidal thinking, one characteristic of dominant masculinity-self-reliance-stood out as a risk factor for suicidal thinking (AOR 1.34; 95% CI 1.26-1.43).

Conclusions - It suggests that one particular element of dominant masculinity-being self-reliant-may place men at increased risk of suicidal thinking. This finding resonates with current theories of how suicidal thinking develops and leads to action. It also has implications for the full gamut of suicide prevention approaches that target males in clinical settings and in the general population, and for our broader society. Further work is needed, however, to confirm the direction of the relationship between self-reliance and suicidality, and to unpack the means through which self- reliance may exert an influence.

a. What is the population of interest in this study?

b. Describe the sample used for this study.

c. What are some strengths of this sampling process?

d. Please comment on the response rate for this study. Why is this important?

e. Can you suggest any potential biases in the sampling process?

Q2. Using the table provided, classify each of the hypothetical studies described below (i-vi) according to:

a. Whether they are a: (2 marks each)

• Cross-Sectional Study (analytical)
• Ecological Study (analytical)
• Cross-Sectional Study (descriptive)
• Case-Control Study
• Retrospective Cohort Study
• Prospective Cohort Study
• Longitudinal Study (descriptive)

b. Give reasons for your choice - justify why it is descriptive or analytical as well as why it is a specific study type - use less than 15 words.

c. Name the measure of frequency (point prevalence, period prevalence, cumulative incidence, incidence rate) or the measure of association (prevalence (rate) ratio, risk ratio, odds ratio, rate ratio) that would be appropriate to use for the study type (note - some studies may have more than one possible measure - please list only one).

Please present your answers to Question 2 in a table (see in attached file) like the one here (you can cut and paste this one).

Studies:

i. Two thousand fully registered hospital-based nurses were identified from registration data and were each sent a survey to ascertain whether they had experienced back pain over the preceding month. Close to 11% of the nurses reported having experienced back pain over the month surveyed.

ii. A research team set out to investigate whether consumption of cured meat products increases the risk of bowel cancer. The researchers were able to identify a good data set held by the European Union for 18 countries for 2016 that had measures of cured meat production and importation. The World Health Organization also had data for these countries on bowel cancer mortality for 2018. Once the data were combined and modelled, the researchers found high consuming countries had slightly elevated levels of bowel cancer mortality in comparison to low consuming countries. The researchers suggested that further studies were required to examine this question.

iii. A researcher suspected a causal link between organophosphates, which commonly occur in farm insecticides, and Parkinson's disease. To investigate this question, she recruited 300 men with Parkinson's disease and matched them with 300 men with no diagnosis of Parkinson's disease. The men were then asked about previous employment on farms. Statistical analysis found that the group of men with a diagnosis of Parkinson's disease were significantly more likely to have reported previous employment on a farm.

iv. A sample of 4,323 healthy men aged 45-65 years without a history of type 2 diabetes or cardiovascular disease (CVD) was followed from 2010 to 2019. Diagnoses of type 2 diabetes and CVD were identified through GP clinic records at yearly intervals. The study found 970 new cases of type 2 diabetes and 739 new cases of CVD.

v. A study set out to investigate if the consumption of artificial sweeteners is a cause of anxiety in children and adolescents. Investigators randomly selected a sample of 1,547 students, 8-16 years of age. The students were provided with a survey that asked about beverage consumption and also included a standardised measure for symptoms of anxiety. The results suggested greater artificially sweetened beverage consumption was associated with a greater presence of symptoms of anxiety.

vi. A total of 1,123 factory workers employed between 1950 and 1957 were identified from the employment records of three large manufacturing plants in the U.S in 1975. Approximately one third of these workers were exposed to asbestos dust, while the remaining workers were not. Between 1957 and 1975 there were 79 deaths due to lung disease in the asbestos exposed group in comparison to 26 deaths from lung disease in the unexposed group. The investigators had postulated that exposure to asbestos dust increases the risk of lung disease.

Q3. In 2005, a research group set out to explore the occurrence of lung disease in workers involved in sandblasting. They recruited 900 workers whose primary duties involved sandblasting. On initial screening, 11 workers were found to meet the diagnostic criteria for lung disease. These individuals continued to work despite being advised of the health risks. The research group ran a study following on from the initial screening. After 10 years all 900 people attended a second health check. At this screening another 39 workers met the criteria for lung disease.

a. What was the prevalence of lung disease at the initial screening? Please express your answer as cases per 1,000 persons and provide an interpretation.

b. How many workers were at risk of developing lung disease at the start of the 10-year follow-up study?

c. Based on the previous information, calculate the cumulative incidence of lung disease and provide the interpretation in cases per 100 people.

Q4. Researchers decided to test the hypothesis that mobile phone use is a cause of primary brain cancer. A case-control study was conducted based on medical records from 10 large hospitals for 2012 to 2014. A total of 246 men and women aged 18 to 65 years with primary brain cancer was matched with 239 controls without brain cancer. All participants in the study were given a structured questionnaire on phone usage habits and then classified as having a history of high mobile phone usage or not having a history of high mobile phone usage. The study findings are presented below in a 2 by 2 table.

		Outcome (primary brain cancer)
		Yes	No
Exposure (high phone usage)	Yes	146	130
	No	100	109
		246	239

a. Name the measure of association that would be most appropriate for this study type.

b. Calculate the appropriate measure of association.

c. Interpret your result.

d. Can we conclude from this study that mobile phones cause/don't cause primary brain cancer? Explain your answer - 50 words max.

Q5. A factory employed a total of 9,789 people. Of these 3,123 were employed in areas where they were exposed to high levels of fine particulate matter, while the remaining 6,666 were not exposed. At the beginning of the study all employees were free from disease. The entire population of 9,789 was reassessed after 10 years to determine whether exposure to fine particulate matter increased the risk of developing a range of diseases associated with the respiratory and cardiovascular systems. The findings at the 10-year assessment are provided in the table below.

		Outcome (respiratory/cardiovascular disease)		Total
		Yes	No
Exposure (to particulate matter)	Yes	523	2600	3123
	No	525	6141	6666
		1048	8741	9789

a. Calculate the appropriate measure of frequency of disease for:

i. The exposed workers.

ii. The unexposed workers.

iii. All the workers.

b. Calculate the appropriate measure of association and interpret your answer.

c. What proportion of the risk of respiratory and cardiovascular diseases in the exposed workers could be due to their particulate matter exposure? Interpret your answer.

Q6. A longitudinal study of the onset of chronic obstructive pulmonary disease (COPD) followed 1,000 men who were smokers between the ages of 40-65 years over a number of years. These men were initially disease free. The investigators first assessed the men after two years and then regularly each two years until the end of the study to see if they satisfied the diagnostic criteria for COPD. The results were as follows:

• 7 new cases of COPD were diagnosed at the first assessment.
• 8 new cases of COPD were diagnosed at the second assessment.
• 9 new cases of COPD were diagnosed at the third assessment.
• 10 new cases of COPD were diagnosed at the fourth assessment.

In addition:

• 8 men elected to withdraw from the study after attending the second assessment.
• 20 men elected to withdraw from the study after attending the third assessment.

a. Based on this information, calculate the cumulative incidence of COPD among this sample and interpret your answer as cases per 1,000 persons.

b. Based on the information, calculate the incidence rate of COPD as cases per 1,000 person-years and interpret your answer.

c. Of the two measures calculated, which is the most appropriate measure of frequency and why?

Attachment:- Assignment File.rar