Nurses’ Health Study
Q1.
The study reflects on the attempts made in investigating the significant risk factors to certain chronic diseases. Specifically, it gives an insight into the research concerning the factors risking women to chronic diseases. Similarly, the study notes that establishing the link between the riskfactors and health outcomes translates to an effective response. The article gives an in-depth reflection of the Nurses’ Health Study (NHS) and NHS II and their commendable contributions in investigating the factors risking women to chronic diseases (Nurses’ Health Study, 2020). It formulates a historical perspective giving an insight into the factors that influenced the decision to use nurses as the study population. Notably, the study points out the adverse effects caused by oral contraceptives due to the increasing usage by most women globally.
Diverse factors dictate the decision to select nurses as the ideal population for the follow-up. First, nurses are suitable because they know about health, thus a perfect group to have an in-depth analysis and monitoring of some of the adverse effects posed by oral contraceptives. Secondly, nurses know about diseases. Nursing education gives nurses an understanding concerning various conditions, thus making the group an ideal choice for the follow-up. With such knowledge, they are motivated to participate in a long-term study.
Cohort studies have distinct strengths and limitations. The regular follow-up is one of the significant advantages of cohort studies since it enables the researchers to have an in-depth analysis of the lifestyles and other factors leading to complications. Besides, the studies adopt questionnaire-based approaches hence leading to an overview of distinct risk factors. A significant weakness is that it requires the researcher to follow a large number of subjects, thus becomes time-consuming and expensive.
Q2.
Ambidirectional and retrospective cohort studies have distinct limitations. The major constraint for the retrospective cohort studies is that they are not effective when dealing with rare diseases. Besides, the utilization of data that was not explicitly designed for the examination may translate to reduced quality outcomes. The study also faces the problem of identifying the fit cohort and comparison group. On the other hand, the need to follow a large number of the subject over a long period is the major limitation of ambidirectional cohort studies. Secondly, the reviews are not valid when dealing with diseases characterized by long latency.
Q3.
Minimizing loss to follow-up is essential because it curtails the chances of compromised study. As such, it threatens the interval validity hence translating to the collection and presentation of data. Avoiding such losses reduce such fatalities. Optimizing participant’s retention is one of the measures towards curtailing the chances of losing follow-up. Secondly, formulating standardized and straightforward systems of evaluation and monitoring are utilized to minimize the loss of follow-up. Similarly, ensuring that ART services are linked with society is a practical approach to reducing the loss of follow-up.
Q4.
- Standardized Mortality Rate- This refers to the ratio between the number of deaths observed in a selected study population and the number of fatalities expected depending on various factors such as sex and age-specific rates. For example, the number of deaths in areas exposed to the risk of cancer is high, as opposed to the number of deaths in the general population.
- Proportional Mortality Rate-This refers to the proportion of deaths in a given population during a specified period, which is attributable to diverse factors/causes (Merrill, 2015). For example, the number of deaths in an industrialized nation is high due to exposure to pollution.
- Person-Time- The concept referring to the estimated time as far as a specific risk is concerned. An example is the calculation of the diagnosis rate of cancer among a given study population for one year.
- Latent Period-Refers to the period between infections by various disease-causing factors such as microorganisms or viruses and the time when the symptoms appear. For example, a person may be infected by an illness during January, but the symptoms appear during April. The period in between is the latent period.
- Induction Period-This refers to the period between the time a person is exposed to disease-causing bacteria and the initial presentation of the disease.
Q5.
A case-control study is conducted to enable the research/health practitioner to come up with a determination concerning the extent of exposure associated with an outcome. The initial process entails the identification of the cases and the controls. The case-control study adopts a retrospective approach because it begins with an outcome followed by the tracing back of the exposures. There is a changing view concerning case-control studies. From a traditional perspective, epidemiologists argued that case-control studies acted as alternatives to cohort studies. The main characteristic feature differentiating the conventional view from other emerging perspectives is the adoption of the comparison of the historical aspects of exposure of cases and controls. This is different from the approaches considered in cohort and experimental study designs. On the other hand, changes contemplated by the epidemiologists since the year 1980 transformed the strategies, thus leading to the modern view. These epidemiologists critiqued the approaches adopted by the traditionalists who considered case-control studies as just reverse to the cohort study. The article selected holds the contemporary view and exemplifies its effectivity in facilitating research. According to the report, case-control studies are advantageous because they are easy to collect and analyze data, inexpensive, and are comparatively quick when compared to other study designs(Aschengrau & Seage, 2020). As such, they are effective in analyzing disease outbreaks and investigating rare medical complications and outcomes. Such advantages show that the authors prioritized the modern view of case-control studies as the most appropriate.
Q6.
The article appreciates the essentiality of selecting the appropriate groups of controls as one of the essential considerations towards an excellent study. The authors consider various approaches used in getting the controls. It points out some of the factors to consider when selecting controls. According to traditional epidemiologists, case-control studies are the direct opposite of cohort studies (Aschengrau & Seage, 2020). One of the primary considerations in principle associated with the distribution of exposure. Secondly, the authors note that a review of the at-risk population as the choice of the control group may be sufficient during a study. The article utilized the matching strategy when collecting the controls. Aspects such as race, sex, and age were considered when selecting the controls. There were several advantages and disadvantages associated with the approach during the selection of the controls. The advantages and disadvantages were as follows.
Advantages
- There was a high probability of eliminating the influence of cofounders that are measurable.
- The sampling process was efficient, thus making it easier to come up with the controls.
Disadvantages
- The approach is time-consuming, especially when dealing with a large population.
- Variables that are matched cannot be utilized during the study.
- Vulnerability to instances of overmatching may lead to vague outcomes.
Q8.
Case-crossover studies refer to an approach where the selection of the subjects is made from the cases. For example, a study that involvesa person who has a prior encounter with the event being studied. The researchers compare exposure over time using a single person, thus enabling him/her to condition the person on stable traits.
Q9.
Odds ratios are utilized during the measurement of association in studies involving case controls because they give an RR approximation that is reasonable as opposed to when used in relative risk. Secondly, the ratios enable the researcher to have an in-depth analysis and understanding of the association measure. In the control cases, (RR) can be calculated using a simple formula, thus making the proportions appropriate.
References
Aschengrau, A., & Seage, G. R. (2020).Essentials of epidemiology in public health.Jones & Bartlett Publishers.
Merrill, R. M. (2015). Introduction to epidemiology.Jones & Bartlett Publishers.
Nurses’ Health Study.(2020). About NHS | Nurses’ Health Study. Retrieved 4 March 2020, from https://www.nurseshealthstudy.org/about-nhs