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.

LOINCActive

LOINC Code 63630-8: How long has it been since you last smoked part or all of a cigarette [PhenX]

Name: LOINC Code 63630-8: How long has it been since you last smoked part or all of a cigarette [PhenX]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:42.802Z

63630-8 is a LOINC code used to identify How long has it been since you last smoked part or all of a cigarette [PhenX] 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 How long has it been since you last smoked part or all of a cigarette. 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 How long has it been since you last smoked part or all of a cigarette. 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
Method: PhenX

What it does not mean

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

Key facts

How long has it been since you last smoked part or all of a cigarette [PhenX]

How long has it been since you last smoked part or all of a cigarette

Note to interviewerRespondents who were classified as a "Smoker" or "Non Smoker" by answering the Tobacco - Smoking Status adolescent protocol, Question 1 as ""Yes"" (Have you ever smoked part or all of a cigarette?) are asked.

Past; Point in time; QNT; Quan; Quant; Quantitative; Random; Smoke; Smokes; Smoking; Smoking cessation time; Tobacco

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

How long has it been since you last smoked part or all of a cigarette [PhenX]Smoking cessation time PhenXHow long has it been since you last smoked part or all of a cigarettePHENXTimePt^Patient

Frequently asked questions

Code details

Code63630-8

SystemLOINC

Display nameHow long has it been since you last smoked part or all of a cigarette [PhenX]

DescriptionHow long has it been since you last smoked part or all of a cigarette

Short nameSmoking cessation time PhenX

ComponentHow long has it been since you last smoked part or all of a cigarette

PropertyTime

TimingPt

System (specimen)^Patient

ScaleQn

MethodPhenX

ClassPHENX

Example unitsD, W, Mo, Y

StatusACTIVE

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.36

Last changed2.65

Part names

How long has it been since you last smoked part or all of a cigaretteTimePt^PatientQnPhenXTime (e.g. seconds)Point 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.