What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 33891-3: Coagulation (PPP control) [Time]

Name: LOINC Code 33891-3: Coagulation (PPP control) [Time]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:21.185Z

33891-3 is a LOINC code used to identify Coagulation (PPP control) [Time] 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 Coagulation. It is commonly used with the system or sample type PPP^Control.

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 Coagulation. It is commonly used with the system or sample type PPP^Control.

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
Method: Coag.surface induced.factor substitution.2H post incubation after addition of normal plasma

What it does not mean

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

Key facts

aPTT.factor substitution 2H post incubation with normal plasma in Platelet poor plasma from Control by Coagulation assay
Coagulation
120 min; 120 minutes; 120min; 2 hours; After; aPTT; aPTT 2h NP; aPTT 2h p Inc; aPTT-FS; Clot; Clottable; Coag; Coagulation assay; Contrl; Control; Fac; Fact; Hematology; Heme; Normal; Plas; Platelet poor plasma; Point in time; PST; QNT; Quan; Quant; Quantitative; Random; Surf; Tilt tube

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

Coagulation (PPP control) [Time]aPTT.factor substitution 2H post incubation with normal plasma in Platelet poor plasma from Control by Coagulation assayaPTT 2h NP PPP ContCoagulationCOAGCoagulation, control BloodTime

Frequently asked questions

Code details

Code33891-3

SystemLOINC

Display nameCoagulation (PPP control) [Time]

DescriptionCoagulation

Short nameaPTT 2h NP PPP Cont

ComponentCoagulation

PropertyTime

TimingPt

System (specimen)PPP^Control

ScaleQn

MethodCoag.surface induced.factor substitution.2H post incubation after addition of normal plasma

ClassCOAG

Example unitss

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.09

Last changed2.82

Consumer names

Coagulation, control Blood

Part names

CoagulationTimePtPPP^controlQnCoag.surface induced.factor substitution.2H post incubation after addition of normal plasmaTime (e.g. seconds)Point in time (spot)Platelet poor plasma^ControlaPTT.factor substitution 2H post incubation with normal plasma

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.