Deck 7: Analytic Epidemiology: Observational Studies

Question 1

Describe different types of studies used in observational and experimental studies in epidemiology.

Answer 1

The different types of studies used in observational study include cohort and case-control studies. These studies look at specific groups of people who have experienced a health condition or event and compare against those who have not experienced the condition. Cohort studies can be prospective or retrospective, which means they either follow a population concurrently through time or start with an outcome and utilize data to go back in time to determine exposure. These studies help the researcher to better understand those who are experiencing a health condition and what may lead to the condition, for example. The experimental study involves the randomized clinical trial and quasi-experimental studies.

Question 2

Describe the strengths and limitations in observational studies.

Answer 2

A strength of a cohort study is that a comparison group is used. However, the limitation of cohort studies includes the issues of information bias and selection bias. The information bias could include an incomplete medical record or inconsistent data collection between the two groups. The selection bias can be related to people not responding to the request to participate, choosing not to participate, or being lost to attrition during a study.

Question 3

Describe how research through the Nurses Health Studies contributes to evidence-based practice.

Answer 3

The Nurses Health Study enhanced the knowledge about many aspects of women's health, including smoking, cardiac disease, and nutrition. This enhanced knowledge opened the opportunity for further study to further understand prevention and treatment measures. These prevention and treatment measures are part of the evidence-based practice that guides patient care today. Without studies like the NHS, significant knowledge would not have been gained about varied health topics, and the basis for further study that lead to EBP would not have been developed.

Question 4

The nurse in an industrial clinic is presenting a plan to the company administration regarding hearing loss among factory workers. The goal is to compare hearing loss with ear protection to hearing loss without hearing protection. Which type of study will give the nurse the most immediate results?

A) Cohort
B) Perspective
C) Observational
D) Retrospective

Question 5

A case-control study was needed to determine an association between the exposure (tobacco) and outcome (lung disease). If the control group (non-smokers) has the same incidences of lung cancer as the smoking group, which additional factor may be a contributor to the disease?

A) General environment
B) Brand of cigarettes smoked
C) The average age of each group
D) The duration of smoking

Question 6

The nurse is performing a comparison study about the incidence of microcephaly between pregnant mothers who traveled to areas where the Zika virus was prevalent and pregnant mothers who did not. A risk ratio (RR) of 1.4 is calculated. Which is the meaning of the RR?

A) The risk is equal between the two groups.
B) There is an increased risk for the exposed group.
C) There is a decreased risk for the exposed group.
D) There is an increased risk for the unexposed group.

Question 7

The original Nurse's Health Study (NHS) was initiated in 1976. For which reason did the study retain 94% of the original participants?

A) Commitment and motivation
B) Availability of research results
C) Employer rewards for participation
D) Reimbursement for all accrued expenses

Question 8

The NHS has contributed to advancing scientific knowledge of women's health and evidence-based public health initiatives. Which is a research result attributed to the NHS?

A) Cigarette smoking in women mildly increases cardiovascular diseases.
B) Postmenopausal obesity is directly linked to incidences of breast cancer.
C) The inclusion of trans-fats in women's diets has several positive effects.
D) Postmenopausal hormone therapies increase the risk of breast cancer.

Question 9

Cohort studies are beneficial when the source of exposure can be determined over time and are easier to conduct when the interval between exposure and outcome is a long time period.

Question 10

If control groups are selected from hospitalized patients with diseases or conditions, researchers must consider issues that may not reflect characteristics of the general population.

Question 11

NHS 3's aims were to include both genders and diverse ethnic and racial participants.

Question 12

In a _________ study, the same person is used as both a case and control.

Question 13

The overall purpose of the Framingham study was to identify common factors that contribute to ________ _______.