A case—control study also known as case—referent study is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. A case—control study produces only an odds ratio, which is an inferior measure of strength of association compared to relative risk. The case—control is a type of epidemiological observational study. An observational study is a study in which subjects are not randomized to the exposed or unexposed groups, rather the subjects are observed in order to determine both their exposure and their outcome status and the exposure status is thus not determined by the researcher. Porta's Dictionary of Epidemiology defines the case—control study as: an observational epidemiological study of persons with the disease or another outcome variable of interest and a suitable control group of persons without the disease comparison group, reference group.
What is a randomized controlled trial?
Case–control study - Wikipedia
Evidence Based Living. You will soon see that almost every commercial uses case studies and testimony of individuals for whom the product has supposedly worked. The problem is that this kind of case study and individual testimony is essentially worthless in deciding if a product or program works. Look at the informercials — they seem to have worked for some people, but what about all the people who failed? To the rescue comes experiments using randomized, controlled designs RCD.
Evidence-Based Practice Toolkit for Nursing
Background: Diabetes mellitus DM is a significant health burden and recent reports suggest that the incidence of diabetes is increasing. Poor knowledge, fear of use of new drugs, and lack of awareness of the importance of the control of the disease are common among primary care physicians caring for diabetes patients. Many diabetes patients continue to be underdiagnosed, undertreated, increased use of expensive acute health-care services, and reduced quality of life. Aims and objectives: The aim was to study the poor control of DM and the associated risk factors associated with Type 2 DM, to spread awareness about DM, to assess the prevalence, treatment, and control of diabetes, to examine the relationship of obesity with raised blood glucose, and finally, to evaluate the effect of the educational level on glycemic control.
In the hierarchy of research designs, the results of randomized controlled trials are considered the highest level of evidence. Randomization is the only method for controlling for known and unknown prognostic factors between two comparison groups. Lack of randomization predisposes a study to potentially important imbalances in baseline characteristics between two study groups.