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LOINC Code 72281-9: Days in therapeutic INR range/Days INR result determined [Ratio]

72281-9 is a LOINC code used to identify Days in therapeutic INR range/Days INR result determined [Ratio] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Days in therapeutic INR range/Days INR result determined. It is commonly used with the system or sample type ^Patient.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Days in therapeutic INR range/Days INR result determined. It is commonly used with the system or sample type ^Patient.

When is it used?

  • Used in lab systems, EHRs, and clinical data exchange.
  • May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
  • Status: ACTIVE
  • Order vs observation: Both

What it does not mean

  • The code identifies the observation or test, not the actual result.

Key facts

Days in therapeutic INR range/Days INR result determined [Ratio]
Days in therapeutic INR range/Days INR result determined
Therapeutic INR range (TTR) is a way of summarizing international normalized ratio (INR) control over time. This term identifies a patient's TTR when the Rosendaal method is used. The Rosendaal method uses linear interpolation to assign an INR value to each day between successive observed INR values. Gaps of greater than 56 days between INR values are not interpolated. After interpolation, the percentage of time during which the interpolated INR values lie within the target therapeutic range is calculated. The formula for TTR for a patient is[Number of days that a patient's interpolated INR result is in therapeutic range] / [Number of days for which the patient has an interpolated INR result]. (See http://www.qualitymeasures.ahrq.gov/content.aspx?id=32739)
Ds INR det; Ds INR range; H&P.HX.LAB; H+P; H+P.HX; Internat norm ratio; International normal ratio; International normalization ratio; International normalized ratio; Lab; P prime; Point in time; QNT; Quan; Quant; Quantitative; Random; Ratios; Rnge; Rto; Ther

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Days in therapeutic INR range/Days INR result determined [Ratio]Ds INR range/Ds INR det Patient-RtoDays in therapeutic INR range/Days INR result determinedH&P.HX.LABRatioPt^Patient

Frequently asked questions

Code details

Code72281-9
SystemLOINC
Display nameDays in therapeutic INR range/Days INR result determined [Ratio]
DescriptionDays in therapeutic INR range/Days INR result determined
Short nameDs INR range/Ds INR det Patient-Rto
ComponentDays in therapeutic INR range/Days INR result determined
PropertyRatio
TimingPt
System (specimen)^Patient
ScaleQn
ClassH&P.HX.LAB
Example units%
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.42
Last changed2.73

Consumer names

Days in Therapeutic INR Range/Days INR Result Determined

Part names

Days in therapeutic INR range/Days INR result determinedRatioPt^PatientQnPoint in time (spot)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.