referentieranges

Referentieranges, or reference ranges, are the ranges of values for a laboratory measurement that are considered typical for a healthy population. They are used to interpret individual test results and to distinguish normal from potentially abnormal findings. A reference range is commonly defined to include the central 95% of values from a reference population, typically spanning from the 2.5th to the 97.5th percentile, and may be presented with a lower and upper limit.

Establishment and variation: Referentieranges are determined from a reference population and often depend on age, sex, and sometimes pregnancy status, ethnicity, and body size. They can also vary with the analytical method, instrument, and reagent lots used by a laboratory. Laboratories may derive their own ranges or adopt published intervals, and ranges may be re-evaluated when methods change or new reference populations are used. Guidelines from professional bodies provide recommendations on how to establish and report reference intervals.

Uses and interpretation: When a patient’s result falls outside the referentierange, the value is flagged as abnormal, but clinical interpretation requires context. A single outside value does not confirm disease, and a value within range does not guarantee health. Clinicians consider biological variation, pre-analytical factors, patient history, and the overall clinical picture when interpreting results.

Limitations: Referentieranges are not universal and may not apply to all populations or individuals. They can be outdated or inappropriate for specific subgroups, such as children, the elderly, or people with certain conditions. Distinctions between reference intervals and decision limits or clinical cutoffs should be understood to guide diagnosis and treatment appropriately.