A Review of a Retrospective Cohort Epidemiological Study (Essay Sample)

A Review of a Retrospective Cohort Epidemiological Study Student’s Name and Number Course Code Instructor Name Date A Review of a Retrospective Cohort Epidemiological Study The research article by Saracci et al. (1991) outlines the findings derived from a study to determine the association between chlorophenoxy compounds and cancer mortality rates. The authors utilize international registers for workers that were exposed to these compounds as well as national records of cancer associated deaths that occurred in the countries under investigation. This analysis presents an overview of the methods used by the researchers in the selection of participants, study design, potential biases, confounding variables and overall conclusion of the validity of the findings. The strengths and limitations of the study are highlighted to establish the generalizability of the study. Moreover, the review utilizes objective approaches in establishing the value of Saracci et al.’s (1991) research and its contribution to epidemiology and human health. Saracci et al’s (1991) decision to employ a fixed cohort study is appropriate for the type of outcome they intended to measure and technicalities involving the inclusion of all subjects in the research. Considering that information collected covered a long period, there was a possibility for the researchers to lack all the necessary information regarding the participants to be included in the study. The fixed cohort design is an appropriate approach to minimize the limitations that could occur due to losses to follow up (Aschengrau and Seage, 2020). Besides, the research type augments the Standardized Mortality Rate (SMR) variable. This measurement is an incidence rate, which according to Aschengrau and Seage (2020) is the preferred when the population is likely to experience losses to follow up. Therefore, the selection of the design in relation to the overall aim and methods of the study is appropriate and this increases the strength of the findings. The article by Saracci et al. (1991) has significant limitations related to selection and recall biases that could negatively impact on the study findings. It is evident that the researchers faced challenges while selecting the study subjects and had to exclude others including those who presented with missing information. In retrospective cohort studies, selection bias often arises when there are persistent losses to follow up, which greatly affects the internal validity of the findings (Howe et al., 2016). Besides, the failure by the researchers to include all the participants from the available records describing a particular selection criteria could also affect the generalizability of the study. The study by Saracci et al. (1991) is also prone to recall bias since data collection approaches revolve the use of questionnaires to obtain information from factory personnel regarding past events. The authors have erred in failing to highlight these challenges and steps that they could have used to minimize these types of biases. A significant research component that the authors have used to improve the validity of their findings is the minimization of errors that could arise from confounding variables. There are chances that cancer mortality rates in the countries under investigation could be strongly associated with other factors such as age and sex of the subjects. The cohort study design, being observational, is not suited for approaches such as randomization that are often used in the design phase to control for the undesired effect of confounding variables (Streeter et al., 2017). When encountered with such a problem, is crucial for the researcher to adjust for possible errors due to extraneous factors by utilizing appropriate approaches during the analysis phase. According to Achengrau and Seage (2020), one of the methods that could be used is standardization of the outcome measure which involves the computation and comparison of adjusted rates across subject groups. Saracci et al. (1991) control for the effect of age in their study considering that it could be a risk factor for death in cancer patient and therefore impact negatively on the interpretation of the association between mortality and chlorophenoxy compounds. Accordingly, the authors’ decision to utilize standardized mortality rate instead of crude mortality rate increases the validity of the findings by eliminating confounder variable effects. Epidemiological context is critical in research studies as it underpins the relevance of the findings. In the study by Saracci et al. (1991), the approach employed revolves around the quantification of the association between cancer-associated mortality rates and exposure to chlorophenoxy compounds. The context within which this study takes place could be described as analytical. Accordingly, this principle of epidemiology revolves around the establishment of quantification measures for variables and understanding the impact of determinants on disease occurrence (Centre for Diseases Control, n.d.). The research article under review highlights the association between two variables but does not infer causality between exposure to chemical compounds and mortality resulting from cancer illnesses. Nonetheless, the findings are relevant in epidemiological studies as they could be used in the formulation of hypotheses that could be further studied upon by researchers. In the context of healthcare service delivery, the study by Saracci et al. (1991) provides sufficient evidence that public health practitioners might utilize in enacting disease prevention and control measures. Additionally, policymakers could employ the study’s findings in approaches geared towards reducing the mortality rate of cancer illnesses in factory workers. A significant limitation of the research study by Saracci et al. (1991) is the nature of the study design which makes it challenging for researchers to determine the causality between the variables. The authors are only interested in determining the incidence rate but it is unclear whether the observed mortality rates are associated with exposure to the chemical compounds. The lack of experimental approaches further hinders the scholars’ attempts in determining the cause and effect analysis, thereby limiting the research to the examination of observed patterns. However, the method that the scholars have used is also vital considering that it allows them to examine and analyze phenomena as they would occur in nature....