Case-controlled studies are a useful form of research. They are observational and utilized to look at aspects impacting disease or outcomes (Tenny et al., 2022). Researchers conducting these studies often begin with a group of cases consisting of persons who have the outcome of interest (Tenny et al., 2022). Work is then completed to determine the exposure (Bonis, 2022). An example would be a group of individuals with a disease compared to a control group to evaluate for risk factor exposure (Bonis, 2022). In a case-control study by Caturegli (2020), groups were evaluated to determine the clinical validity and utility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The study was conducted using 115 individuals hospitalized at John Hopkins Hospital in Baltimore, Maryland and testing for SARS-CoV-2 was completed using nucleic acid amplification testing (NAAT) on nasopharyngeal swabs (Caturegli, 2020). The researchers utilized clinical record review to classify individuals into a SARS-CoV-2 group and control group consisting of non-SARS-CoV-2 individuals (Caturegli, 2020). Serum IgG and IgA antibodies were assessed for the SARS-CoV-2 spike protein by using enzyme-linked immunosorbent assay (Caturegli, 2020). The IgG assay was determined to have high sensitivity and specificity when performed 14 days following symptom onset (Caturegli, 2020). It was determined that antibodies to SARS-CoV-2 predicted the odds of developing acute respiratory distress syndrome, which increased by 62 percent for every two-fold increase in IgG (Caturegli, 2020). The researchers concluded that SARS-CoV-2 antibody testing was useful in identifying infection when measured at least 14 days following symptom onset, was linked with clinical severity, and provided valuable diagnostic support in patients testing negative by NAAT but remain clinically suspicious for SARS-CoV-2 (Caturegli, 2020). This study was conducted by retrospective review with the limitation of using small sample size (Caturegli, 2020).

There are differences among case-controlled studies and others, such as randomized controlled trials (RCTs). A fundamental difference in these two studies involves the assignment of individuals to each study. In RCTs, individuals are randomly selected and assigned to groups resulting in decreased bias and more equivalent grouping (Vitale & Cupp, 2020). This enhances the chance of the outcome being attributed to the intervention (Vitale & Cupp, 2020). In case-controlled studies, there is no randomization of who is chosen for the groups or study. Individuals are selectively chosen who possess a certain attribute and are assigned to a group, and other individuals who do not possess that attribute are chosen and assigned to a control group (Vitale & Cupp, 2020). The researchers from the SARS-CoV-2 case-controlled study mentioned that bias was a limitation in their study (Caturegli, 2020). The studies also differ in that RCTs are experimental in which subjects are assigned to two or more interventions (Bonis, 2022). Case-controlled studies are observational and utilized to review factors associated with disease or outcomes (Tenny et al., 2022).

Case-controlled studies have several advantages. One benefit is that rare diseases may be studied (Tenny et al., 2022). Participants in a rare disease case-controlled study could be observed over a longer time allowing for more cases to be added to study as incidence occurs (Tenny et al., 2022). This study allows for evaluation of current disease cases as well as historical disease cases to be included in the same study (Tenny et al., 2022). Also, case-controlled studies allow for consideration of multiple variables that may impact a disease (Tenny et al., 2022). An example would be a case-controlled study regarding obesity and review of multiple factors that may impact the disease, such as occupation, work status, income, food intake, alcohol use, tobacco use, physical activity, family history, comorbidities, and others. Case-controlled studies have also been helpful during disease outbreaks when potential associations and exposures need to be identified (Tenny et al., 2022). They are one of the initial studies utilized to examine the link between an exposure and a disease (Tenny et al., 2022). Case-controlled studies may have unequal numbers in cases versus control groups to increase the power of the study (Tenny et al., 2022).

There are several disadvantages and limitations of case-controlled studies. This includes the risk of bias and confounding variables (Vitale & Cupp, 2020). Bias and confounding can lead to inaccurate results (Vitale & Cupp, 2020). Confounding occurs when it appears a cause is related to the outcome, but another variable is responsible for the impact (Vitale & Cupp, 2020). Recall bias is also a limitation in that participants with the outcome may recall and report exposures compared to those without the outcome (Tenny et al., 2022). This may lead to confirming existing associations between exposure and disease when they do not exist (Tenny et al., 2022). While case-controlled studies may be useful to identify correlation between an exposure and an outcome, they are not used to establish causation (Tenny et al., 2022). Also, in case-controlled studies, the researcher must ensure that the case and control groups are properly chosen to ensure validity of potential correlations between exposure and disease states (Tenny et al., 2022).

Correlational studies are observational and utilized to determine aggregate or population characteristics (Vitale & Cupp, 2020). They can identify ongoing patterns, seasonal trends, and event-related clusters (Vitale & Cupp, 2020). Whereas case-controlled studies aim to determine exposure-related outcomes, correlational studies are used to collect data on populations rather than individuals and other variables may not be controlled (Vitale & Cupp, 2020). An example of a correlational study is one conducted by Avci and Ayaz-Alkaya (2021) with the aim of identifying the anxiety level, social support, and satisfaction of family members of patients admitted to the intensive care unit (ICU). A descriptive, correlational study was completed including a sample of 250 family members in ICUs with data collected using the Multidimensional Perceived Social Support Scale, the State-Trait Anxiety Inventory, and the Family Satisfaction in the Intensive Care Unit scale (Avci & Ayaz-Alkaya, 2021). The results consisted of a negative correlation identified between family satisfaction of the ICU and state anxiety, and a negative relationship between satisfaction of the ICU and trait anxiety of the participants (Avci & Ayaz-Alkaya, 2021). There was also a significant relationship between the state anxiety level, trait anxiety level, the perceived social support, and satisfaction of family members and their sociodemographic factors (Avci & Ayaz-Alkaya, 2021). The researchers concluded that the family members’ anxiety levels were high, and their social support and satisfaction of the ICU were at a moderate level (Avci & Ayaz-Alkaya, 2021). Correlation was identified between anxiety levels, ICU satisfaction, and perceived social support of families (Avci & Ayaz-Alkaya, 2021). As described by Vitale and Cupp (2020), this study exhibits the characteristics of an existing correlation between factors but does not indicate or assume a causal relationship.

The research pyramid is a useful tool for determining which studies have the strongest evidence for application to medical practice. The hierarchy of studies conveys the idea that not all evidence is equivalent (Murad et al., 2016). Studies are placed on levels of the pyramid with the most validity being toward the top. (Murad et al., 2016). The weaker studies are placed at the bottom including basic science and case series, followed by case-controlled studies next to the bottom, then cohort studies, randomized controlled trials, and systematic reviews and meta-analysis at the top (Murad et al., 2016). With the case-controlled studies being placed on the next level from the bottom, this indicates they are more valid and useful in practice than basic science and case series but have less certainty in ability to apply to practice than cohort studies, randomized controlled studies, systematic reviews, and meta-analysis. The main purpose of the pyramid is to imply increasing validity and applicability based on the level of the study, with an emphasis on the lower evidence sources on the pyramid being the least preferred in practice as they require more expertise and effort to identify, appraise, and apply (Murad et al., 2016). The hierarchy of evidence pyramid is a useful tool for the advanced practice nurse to utilize when determining which study is the most evidence-based to apply to practice.

References

Avci, M., & Ayaz-Alkaya, S. (2021). Anxiety, social support and satisfaction of patients’ families in intensive care units: A descriptive-correlational study. Journal of Clinical Nursing, 31(19), 2765-2773. https://doi-org.chamberlainuniversity.idm.oclc.org/10.1111/jocn.16094

Bonis, P. A. (2022). Glossary of common biostatistical and epidemiological terms. UpToDate. Retrieved September 14, 2022, from https://www.uptodate.com/contents/glossary-of-common-biostatistical-and-epidemiological-terms?

Caturegli, G., Materia, J., Howard, B. M., & Caturegli, P. (2020). Clinical validity of serum antibodies to SARS-CoV-2: A case-control study. Annals of Internal Medicine, 173, 614-622. https://doi.org/10.7326/M20-2889

Murad, M. H., Asi, N., Alsawas, M., & Alahdab, F. (2016). New evidence pyramid. Evidence-Based Medicine, 21(4), 125-127. https://doi.org/10.1136%2Febmed-2016-110401

Tenny, S., Kerndt, C. C., & Hoffman, M. R. (2022). Case control studies. https://pubmed.ncbi.nlm.nih.gov/28846237/Links to an external site.

Vitale, P. A., & Cupp, L. (2020). Epidemiological methods and measurement in population-based nursing practice: Part I. In A. L. Cupp (Ed.), Population-based nursing: Concepts and competencies for advanced practice (3^rd ed., pp. 53-86). Springer Publishing Company, LLC.

Vitale, P. A., & Cupp, L. (2020). Epidemiological methods and measurement in population-based nursing practice: Part II. In A. L. Cupp (Ed.), Population-based nursing: Concepts and competencies for advanced practice (3^rd ed., pp. 87-108). Springer Publishing Company, LLC.

Our team of expert nursing writers at Nursing Assignment Service can help you with your NR 503 Week 3 Discussion, place your order here.