True Research Design Randomized Control Trial

Discussion Q’s

Atherosclerosis is disease in which cholesterol and lipids gather on the walls of a person’s arteries (Jebari-Benslaiman et al., 2022). These substances form plaque, which prevents normal blood flow by restricting the space through which blood can move. The arteries become tighter and tighter like a clogged pipe, making it harder for the heart to pump the same amount of blood throughout the body. This process begins with injury to the endothelium, which is the inner lining of the artery. Injury can occur as a result of smoking or diabetes or some other problem. Lipids accumulate on the endothelium as a result of permeability caused by the injury. Oxidation follows, triggering inflammation.

Next, monocytes begin to affix to the endothelium and produce foamy, fatty cells (Mehu et al., 2022). More inflammation occurs due to cytokine build-up, and plaque formation then results. Lipids, foam cells, new cell growth combine to facilitate additional plaque development. Plague may become calcified or it may stay soft and rupture. If plague stays soft and ruptures, it exposes thrombogenic material and a thrombus forms. This formation can be causes a complete occlusion of an artery. Heart attack, stroke, arterial disease—any might occur soon thereafter (Mehu et al., 2022).

Overall, atherosclerosis is a process that begins with an injury caused by poor health lifestyle choices—such as bad diet or smoking or alcohol. These choices injure the arterial walls, and the body responds in an attempt to fix it. However, lipids affix themselves to the wall first, and build-up of plaque ensues. To prevent the artery from closing off, it is best to prevent the build-up in the first place and to avoid lifestyle choices that can injure the artery’s inner lining. This means preventing diabetes, not smoking, and maintaining a healthy lifestyle through proper diet and exercise.

References

Jebari-Benslaiman, S., Galicia-García, U., Larrea-Sebal, A., Olaetxea, J. R., Alloza, I.,

Vandenbroeck, K., ... & Martín, C. (2022). Pathophysiology of atherosclerosis. International journal of molecular sciences, 23(6), 3346.

Mehu, M., Narasimhulu, C. A., & Singla, D. K. (2022). Inflammatory cells in

atherosclerosis. Antioxidants, 11(2), 233.

A study is said to have internal validity when it can establish that a cause-effect relationship exists between the independent variable and the dependent variable. There should be no evidence of influence from other variables that could affect the relationship. Internal validity can be supported in different ways, such as randomization of the sample, control groups (to control for variables), and blinding (to remove or at least reduce bias) (Hunziker et al., 2021).

External validity refers to the generalizeability of the study’s findings. For example, if a study can be duplicated with a different sample or in a different setting, it may have external validity. Replication is one way to support external validity, as is random sampling. However, the research design itself is probably the best way to support external validity, by designing it to mimic real-world conditions as closely as possible.

A pre-experimental design has no random assignment or control group. For example, a study of the effectiveness of a vaccine with this design would be to give the vaccine to everyone and the effect is measured. There is little internal validity in this design. Quasi-experiments are a little better in that there is a control group, but it is usually not equivalent to the experimental group, and there is no randomization, either. So, internal validity is a little better, but still not the best. True experimental design uses randomization and control groups as well as some manipulation of the independent variable (Duckett, 2021). The best example of this would be a randomized control trial of a new drug, where participants are randomly assigned to an experiment and an equal control group which receives only a placebo, and no one knows which group they are in. That way, the participants are blinded, and researchers themselves are blinded because they, too do not know which group participants are in until after the fact.