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Corrected reticulocyte count and RPI

Assesses marrow response to anemia by correcting reticulocyte percentage for anemia degree and maturation time.

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Check the population, units and version. The result shows the formula or classification; it does not make an automatic treatment decision.

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Method · Limits of application

Hillman 1969: reference hematocrit 45%; maturation 1/1.5/2/2.5 with local bands 40/30/20

Reticulocyte correction depends on the change in maturation time associated with anemia severity. The original study used phlebotomy-induced anemia in normal people; simplified local ranges were not confirmed by the abstract. The index alone does not determine the cause or marrow reserve in any disease.

Conditions of use

Check the population, units, inclusion and exclusion criteria, and version in the original source. A result alone does not establish a diagnosis, discharge decision or prescription.

Documented parameters

Reticulocytes · %
Hematocrit · %

4/4 reference cases checked. Numerical tests are not clinical validation.

Sources and documentation

Documented formula

Transcribed from the source or a recorded revision; this is not a clinical recommendation.

Corrected reticulocytes (%) = reticulocytes (%) × hematocrit ÷ 45.

RPI = Corrected reticulocytes ÷ maturation factor, the factor is maturation time in blood, in days: 1.0 (hematocrit ≥ 40%); 1.5 (30–39%); 2.0 (20–29%); 2.5 (< 20%).

References

Hillman RS. Characteristics of marrow production and reticulocyte maturation in normal man in response to anemia. J Clin Invest, 1969.

Identifier: indice-de-producao-reticulocitaria

Original clinical content: Brazilian Portuguese.

Method version

Hillman 1969: reference hematocrit 45%; maturation 1/1.5/2/2.5 with local bands 40/30/20

indice-de-producao-reticulocitaria@native-2026-10-03+251882d75bf7

Source for the active edition

The bibliographic edition identifies the source. By itself, it proves neither full conformity of the formula nor clinical approval.

Synthetic cases checked (4)

Synthetic cases for checking the implementation, with no patient data.

Case 1

reference-001

Inputs

Reticulocytes: 6 %
Hematocrit: 25 %

{
  "ret": 6,
  "ht": 25
}

Expected result

{
  "corr": 3.333,
  "mf": 2,
  "ipr": 1.667
}

Actual result

{
  "corr": 3.3333333333333335,
  "mf": 2,
  "ipr": 1.6666666666666667
}

Case 2

reference-002

Inputs

Reticulocytes: 10 %
Hematocrit: 30 %

{
  "ret": 10,
  "ht": 30
}

Expected result

{
  "corr": 6.667,
  "mf": 1.5,
  "ipr": 4.444
}

Actual result

{
  "corr": 6.666666666666667,
  "mf": 1.5,
  "ipr": 4.444444444444445
}

Case 3

reference-003

Inputs

Reticulocytes: 5.4 %
Hematocrit: 25 %

{
  "ret": 5.4,
  "ht": 25
}

Expected result

{
  "corr": 3,
  "ipr": 1.5
}

Actual result

{
  "corr": 3,
  "mf": 2,
  "ipr": 1.5
}

Case 4

reference-004

Inputs

Reticulocytes: 9 %
Hematocrit: 20 %

{
  "ret": 9,
  "ht": 20
}

Expected result

{
  "corr": 4,
  "ipr": 2
}

Actual result

{
  "corr": 4,
  "mf": 2,
  "ipr": 2
}

Code and reproducibility

This tool’s code on GitHub

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Sources, version and reproduction instructions

The code tests are technical checks. Clinical approval and professional translation review are recorded separately.

Relationship with cancer research

General context — relationship to be defined

A resource for general clinical contexts. This edition does not assign a specific oncological relationship; selecting it for a study requires a justified question, population and purpose.