Reference Range

The reference interval, bounded by two reference limits, corresponds to the interval calculated according to the distribution of the values obtained from populations of healthy subjects.

The interval is predefined, and corresponds to, for example, 95% of the reference population. It may vary depending on the type of primary sample and the method used.

Target value

The target value of an analysis corresponds to a pre-established value which, when reached, is accompanied by the improvement of symptoms specific to the disease in question.

Within the framework of the diagnosis in preventive medicine, the physician in charge will be able to use the target values to define the prevention measures adapted to his patient in order to maintain or obtain values considered as optimal in preventive medicine.


Decision threshold. It determines when a test result is to be evaluated positively or negatively. It can differ from laboratory to laboratory.

Therapeutic margin

The therapeutic range corresponds to the area of plasma concentrations associated with a high probability of efficacy and a low probability of toxicity linked to the dose of a drug.

Based on the therapeutic range, the dosage to be used can be estimated on a statistical basis. It is used to predict the range of therapeutic activity, but cannot be used alone as an efficiency criterion.