Jadad scale

The Jadad scale, referred to in many publications as a Jadad score or Oxford - scale, is a simple evaluation scheme ( tool) to analyze the quality of clinical intervention studies. The name is derived from Alejandro Jadad ( born 1963 ), a Colombian physician and advocate of evidence-based medicine, which developed this model in Oxford.

Importance

The Jadad scale is currently the only validated scale to assess the methodological quality of studies. It is therefore assessed the quality of the conduct of a study and not the quality of the results. However, can be drawn from the study quality draw conclusions about the quality of the results.

Construction

The Jadad scale consists of dichotomous questions, the answer is directly correlated with the quality of the studies. The five questions relate to the following points:

• Randomization
• Blinding
• Drop-outs ( failures, college dropout )

The questions are:

Then the points are added up. After Jadad, studies with less than three points of poor quality. To avoid systematic error (bias ) the evaluation of at least two persons must be performed.

Criticism

Although in principle the quality of planning and implementation to evaluate a study using the Jadad scale, the quality of the publication is often rated. A methodology unclean shown does not immediately mean that the study was conducted unclean and vice versa.

When interpreting the Jadad scale in addition it should be noted that it is only for the valuation of certain study types suitable (eg therapy studies). For some types of studies (eg, cohort studies, case -control studies, diagnostic studies or observational studies ), this scale is little or not at all.