LOINCActiveObservation

LOINC Code 81266-9: Date of fever onset

81266-9 is a LOINC code used to identify Date of fever onset 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 Date of fever onset. 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 Date of fever onset. 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: Observation

What it does not mean

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

Key facts

  • Date of fever onset
  • H+P; H+P.HX; P prime; Point in time; QNT; Quan; Quant; Quantitative; Random

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

Date of fever onsetH&P.HXDatePt^PatientQnPoint in time (spot)

Frequently asked questions

Code details

Code81266-9
SystemLOINC
Display nameDate of fever onset
Short nameDate of fever onset
ComponentDate of fever onset
PropertyDate
TimingPt
System (specimen)^Patient
ScaleQn
ClassH&P.HX
Example unitsMMDDYY
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released2.56
Last changed2.56

Part names

Date of fever onsetDatePt^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.

LOINC Code 81266-9 | HealthAssure