The clinical study design is a methodology by which health-care researchers create controlled studies that assess the effects of a pharmaceutical product on humans. Clinical research involves the investigation of new pharmaceutical products for use in treating a disease or for the treatment of symptoms of an ailment. In addition, clinical trials aim to establish safety, effectiveness and the long-term consequences of an new pharmaceutical product. There are two categories of clinical trials: randomized trials and case-controlled trials. Randomized trials are those in which the subjects are given placebos or other treatments in order to determine the effectiveness of a new pharmaceutical product; case-controlled trials are those in which patients are administered substances and monitored for specific effects of a new pharmaceutical product.
A well-designed observational study design ensures the proper functioning of any trial. An observational study is one in which researchers follow up on the subject of interest so as to determine the health impact it may have on a patient after its consumption. These days, most researchers perform observational studies using large registries such as the United States Nurses’ Health Study (USNHS); the Nurse Practitioner Data Bank (NPDF) and the Canadian Nurses’ Program (CNP).
However, although these are the most common research designs, other techniques can also be used when conducting research on new pharmaceuticals or medical devices. Another important factor to consider is the study design itself. The key components of an effective study design include a procedure for recruiting subjects, an explanation of the procedure and methods used to recruit them, data collection at both the end of the study and in the analysis phase, a comparison of the final outcome between the experimental and control group, and statistical analysis of the data. It should be noted that all of these components are interconnected and that the failure of any of them can seriously undermine the validity of the results.
Types of Study Design
There are several different types of study designs used in clinical research. One of the most common is called the double-arm, multiple-arm, and observer-coverage design. The most familiar example of this is the clinical trial, which uses larger numbers of volunteers in each arm to determine whether the new treatment is more effective than the placebo. Another type of design is called the descriptive study design, which compares health conditions between groups.
Although some research study designs are powered with specific parameters, some use more general ones. For instance, a survey-based study may have a very different set of criteria from those needed for a laboratory study. Furthermore, because of the many factors involved in determining whether a new medication is effective, the possible confounders cannot be controlled. Another limitation is that the length of time that the treatment was administered has long been considered to affect the drug’s effectiveness. In addition, both long-term and short-term medications can have different effects on people with various medical conditions.
There are also two main types of study design: experimental and observational. An experimental study design involves trying out an intervention and tracking how it works. Outcomes can be compared between groups at specific points in time using statistics. However, there is no attempt to account for the confounders or the factors that could have influenced the results. The focus is on testing the effects of the intervention without controlling for the other factors. This type of study design has fewer limitations than the study design used in observational studies.
Although many advantages can come from a well-designed study design, it has certain disadvantages as well. One of the biggest disadvantages of this method is that the risk factor is not measured at the time of recruitment. Thus, the true benefit and risk factors cannot be determined. It may also take a long time to analyze and interpret the results, making the results more vague than useful.
A Cohort Study is a better alternative. A Cohort Study allows researchers to follow people over a long period of time, thus providing more accurate estimates. Unlike observational studies, a Cohort Study allows researchers to adjust the variables of interest simultaneously. Another advantage of a Cohort Study is that it is theoretically consistent with generalizations from past studies. Thus, a Cohort Study may provide a better estimate of the effect of an intervention than say an observational study could.