Editing Reference range (section)

==General drawbacks==
For standard as well as optimal health ranges, and cut-offs, sources of [[Accuracy and precision|inaccuracy and imprecision]] include:

* Instruments and lab techniques used, or how the measurements are interpreted by observers. These may apply both to the instruments etc. used to establish the reference ranges and the instruments, etc. used to acquire the value for the individual to whom these ranges is applied. To compensate, individual laboratories should have their own lab ranges to account for the instruments used in the laboratory.
* [[Risk factor (epidemiology)|Determinants]] such as age, diet, etc. that are not compensated for. Optimally, there should be reference ranges from a reference group that is as similar as possible to each individual they are applied to, but it is practically impossible to compensate for every single determinant, often not even when the reference ranges are established from multiple measurements of the same individual they are applied to, because of [[test-retest reliability|test-retest]] variability.

Also, reference ranges tend to give the impression of definite thresholds that clearly separate "good" or "bad" values, while in reality there are generally continuously increasing risks with increased distance from usual or optimal values.

With this and uncompensated factors in mind, the ideal interpretation method of a test result would rather consist of a comparison of what would be expected or optimal in the individual when taking all factors and conditions of that individual into account, rather than strictly classifying the values as "good" or "bad" by using reference ranges from other people.

In a recent paper, Rappoport et al.<ref>{{cite bioRxiv|last1=Rappoport|first1=Nadav|last2=Paik|first2=Hyojung|last3=Oskotsky|first3=Boris|last4=Tor|first4=Ruth|last5=Ziv|first5=Elad|last6=Zaitlen|first6=Noah|last7=Butte|first7=Atul J.|date=2017-11-04|title=Creating ethnicity-specific reference intervals for lab tests from EHR data|biorxiv=10.1101/213892}}</ref> described a novel way to redefine reference range from an [[electronic health record]] system. In such a system, a higher population resolution can be achieved (e.g., age, sex, race and ethnicity-specific).