A case-control study was conducted to investigate if exposure to zinc oxide is a more effective skin cancer prevention measure.The study involved comparing a group of former lifeguards that had developed cancer on their cheeks and noses (cases) to a group of lifeguards without this type of cancer (controls) and assess their prior exposure to zinc oxide or absorbent sunscreen lotions.
A case-control study was conducted to investigate if exposure to zinc oxide is a more effective skin cancer prevention measure.The study involved comparing a group of former lifeguards that had developed cancer on their cheeks and noses (cases) to a group of lifeguards without this type of cancer (controls) and assess their prior exposure to zinc oxide or absorbent sunscreen lotions.Tags: World War 2 Essay TopicsIn Radiography EssayObjectives EssaysUt Homework Answers PhysicsHelp Solve Algebra ProblemsAlankit AssignmentsPygmalion EssayCause And Effect Of Alcohol Abuse EssayEssay Writing Competitions In 2015Essay For High School Admission
In this situation, one may choose to assay all of the cases, and also, for each case, select a certain number of women to assay from the risk set of participants who have not yet failed (i.e.
those who have not developed breast cancer before the particular case in question has developed breast cancer).
This benefit is pronounced when the covariate of interest is biological, since assessments such as gene expression profiling are expensive, and because the quantity of blood available for such analysis is often limited, making it a valuable resource that should not be used unnecessarily.
As an example, of the 91,523 women in the Nurses' Health Study who did not have cancer at baseline and who were followed for 14 years, 2,341 women had developed breast cancer by 1993.
The nested case–control study can be analyzed using methods for missing covariates.
Case Control Study Epidemiology Ppt Sat Essay Prompt Questions
The NCC design is often used when the exposure of interest is difficult or expensive to obtain and when the outcome is rare.Does it use appropriate inclusion and exclusion criteria?There is a suspicion that zinc oxide, the white non-absorbent sunscreen traditionally worn by lifeguards is more effective at preventing sunburns that lead to skin cancer than absorbent sunscreen lotions.Boubekri, M., Cheung, I., Reid, K., Wang, C., & Zee, P. Impact of windows and daylight exposure on overall health and sleep quality of office workers: a case-control pilot study.This pilot study explored the impact of exposure to daylight on the health of office workers (measuring well-being and sleep quality subjectively, and light exposure, activity level and sleep-wake patterns via actigraphy).Usually, the exposure of interest is only measured among the cases and the selected controls.Thus the nested case–control study is more efficient than the full cohort design.The analysis of a nested case–control model must take into account the way in which controls are sampled from the cohort.Failing to do so, such as by treating the cases and selected controls as the original cohort and performing a logistic regression, which is common, can result in biased estimates whose null distribution is different from what is assumed.This study would be retrospective in that the former lifeguards would be asked to recall which type of sunscreen they used on their face and approximately how often.This could be either a matched or unmatched study, but efforts would need to be made to ensure that the former lifeguards are of the same average age, and lifeguarded for a similar number of seasons and amount of time per season.