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 63646-4: During the past 30 days, on how many days did you use drugs [PhenX]

Name: LOINC Code 63646-4: During the past 30 days, on how many days did you use drugs [PhenX]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:42.802Z

63646-4 is a LOINC code used to identify During the past 30 days, on how many days did you use drugs [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 During the past 30D, on how many D did you use drugs. 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 During the past 30D, on how many D did you use drugs. 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

During the past 30 days, on how many days did you use drugs [PhenX]
During the past 30D, on how many D did you use drugs
Count/time; Dextro; Drug; Durg 30D freq; Last; nRate; Number rate; Number Rate = Count/Time; QNT; Quan; Quant; Quantitative

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

During the past 30 days, on how many days did you use drugs [PhenX]Durg 30D freq nRate PhenXDuring the past 30D, on how many D did you use drugsPHENXNRat30D^Patient

Frequently asked questions

Code details

Code63646-4

SystemLOINC

Display nameDuring the past 30 days, on how many days did you use drugs [PhenX]

DescriptionDuring the past 30D, on how many D did you use drugs

Short nameDurg 30D freq nRate PhenX

ComponentDuring the past 30D, on how many D did you use drugs

PropertyNRat

Timing30D

System (specimen)^Patient

ScaleQn

MethodPhenX

ClassPHENX

Example unitsdays/mo

StatusACTIVE

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.36

Last changed2.65

Part names

During the past 30D, on how many D did you use drugsNRat30D^PatientQnPhenXDuring the past 30 days, on how many days did you use drugsNumber Rate30 days

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.