Prospective cohort study

A prospective study (Latin prospecto: ausschauen ) is to test the hypothesis of medical or psychological effectiveness of a treatment method with prior determination of which hypothesis to be tested. The data in accordance with the hypothesis notably be collected in contrast to the retrospective evaluation of already existing data.

The term prospective is " ahead " in the high-level language in the sense of " the possibility for" and " the further development concerning " related.

The prospectivity of a study says something about the timing of hypothesis generation and data acquisition. The data in such a study will be compiled according to the hypothesis formation, specifically for testing the hypothesis. One advantage is that the data material can then be tailored to the requirements of the study.

In a retrospective study, however, you can search for existing databases, eg after installation of the hypothesis and take data from it - then this may not fit exactly to the requirements of the study, on the other hand, this method is often less costly and time- intensive.

Prospective studies can be divided into experimental prospective studies and observational prospective studies. In the experimental study, the strength of the independent variable and its assignment to the individual subjects by the investigator is usually performed by randomization. In the observational study finds such an allocation does not occur.

Example

If one wants to investigate the effect of smoking on the development of lung cancer, there are two prospective approaches:

As you can see, the second solution is not ethically justifiable always, even though they theoretically achieve safer results because they, for example, prevents there is a third variable that affects both the independent variable and the dependent variable.